All these mixed varnas you mentioned originated later in the Vedic society. The original Varna system consisted of only 4 Varnas(kind of 4 races of men) with distinct genes and their attributes where marriages was to be done in the same varna. This was also explained in Geeta which is summary of shrutis Vedas and Vedanta.
Geeta Chapter 18
Bhagavad Gita 18.41 The duties of the Brahmins, Kshatriyas, Vaishyas,
and Shudras—are distributed according to their qualities, in
accordance with their guṇas.
Bhagavad Gita 18.42 Tranquility, restraint, austerity, purity,
patience, integrity, knowledge, wisdom, and belief in a
hereafter—these are the intrinsic qualities of work for Brahmins.
Bhagavad Gita 18.43 Valor, strength, fortitude, skill in weaponry,
resolve never to retreat from battle, large-heartedness in charity,
and leadership abilities, these are the natural qualities of work for
Bhagavad Gita 18.44 Agriculture, dairy farming, and commerce are the
natural works for those with the qualities of Vaishyas. Serving
through work is the natural duty for those with the qualities of
Bhagavad Gita 18.45 By fulfilling their duties, born of their innate
qualities, human beings can attain perfection. Now hear from me how
one can become perfect by discharging one’s prescribed duties.
Bhagavad Gita 18.46 By performing one’s natural occupation, one
worships the Creator from whom all living entities have come into
being, and by whom the whole universe is pervaded. By such performance
of work, a person easily attains perfection.
' Braahmanosya mukhmaasita, baahu raajanya krita. Uru tadasya
yadvaishyaha padabhyaam shudro ajaayata. '
" From his(God) mouth emerged Brahmins(priests), from shoulders
emerged Kshatriyas(warriors or governors), from thighs emerged
Vaishyas(traders, businessmen, agriculturist) and from his feet
emerged Shudras(serving class) " (Purushsukta -Rig Veda)
These varnas are parts of Brahman translates to Nirguna Purusha and Triguna Prakriti eventually, are also 4 Puruṣārtha or underlying backbone of society and its people.
Brahmin = Nirguna Purusha(head/Wisdom & Moksha)
Kshatriya = Satva Guna (hands/Protection & Dharma)
Vaishya = Rajas Guna (stomach/Reproduction & Artha)
Shudra = Tamas Guna (feet/Physical work & Kama)
Krishna, who was Saguna Brahman explained that how the knowledge of Geeta/Vedas were given to the ruling kings Manu in the beginning of current Manvantra and transferred to their progenies later.
Bhagavad Gita 4.1 The Supreme Lord Shree Krishna said: I taught this
eternal science of Yog to the Sun-god, Vivasvan, who passed it on to
Manu; and Manu in turn instructed it to Ikshvaku.
But as Yugas descended from Satyuga to Kaliyua, people forgot Dharma and started practicing inter-varna marriages out of lust, adultery, or greed of gold leading to confused varnaless, caste-system of present society, for example Mlecchas and all other barbaric races. Hence, names of these mixed varnas were coined and occupations assigned later by Manus and their progenies and Brahmin scholars of their time as Vedas is silent about occupations of mixed varnas owing to their mixed genes and random affinity towards occupation of scholar, warrior, businessman or servant and were given lowly works in ancient Vedic society. Thats why several of these offspings of mixed-varna preferred to leave ancient Vedic society and migrated all around Eurasia, despite Indian subcontinent's rich favorable climate yet strict society to become varnaless and non-vedic Mlecchas of today. This is also known as Indo-Aryan migration which was twisted by European scholars and Hitler where they claim that Aryans originated in some parts of Europe when they themselves call Aryans pagan and follow Jewish Abrahamic religions and their customs today. Thats why Sanskrit share so much similarities with PIE languages and the chief Vedic Gods Indra and the sky father god Dyaus of Rigveda became to be known as Thor and Zeus/Jupiter respectively in European cultures.
Manu Smriti 10.4 The Brāhmaṇa, the Kṣatriya and the Vaiśya are the
three twice-born castes; the fourth is the one caste, Śūdra; there is
Manu Smriti 10.24 ‘Confused castes’ are produced by infidelity among
the castes, by the marrying of women unfit for marriage, and by the
neglect of one’s duties
Eugenics, which is spiritual science, is a part of Vedic society based on laws of nature and failing to abide by it alone leads to evil souls taking birth in aristocrat clans. Birth, Death and marriage of any human jiva is controlled by nature and its law as these things impact the entire society for thousands of years on earth in the form of their progenies and their contribution to society. Humans are not animals who are allowed to mate randomly, even animals are controlled by nature in the form of mating season. Man is given intellect and Shastras to abide by them, failing to follow, leads to catastrophes in offsprings. Thats why a common man, of today's Kaliyuga, an image of God in reality is so atheist, weak, greedy and materialistic compared to divine wise kings Manus and their offsprings, the mind born of Brahma, the personification of Brahman via Vivasvan and Saptrishis. Thats why monarchy was removed and democracy came into our current society where any common man can become minister by his Karmas.
Thats why evil Ravana took birth from Brahmin father through deception in Treta Yuga when Dharma prevailed but Kamsa or asura Kalnemi took birth in Yaduvansha automatically because of collapse of following Dharma shastras by their forefathers during Dwapra Yuga and Krishna avatar had to take birth to annihilate them later.
Bhagavad Gita 1.38 – 1.39 Their thoughts are overpowered by greed and
they see no wrong in annihilating their relatives or wreaking
treachery upon friends. Yet, O Janardan (Krishna), why should we, who
can clearly see the crime in killing our kindred, not turn away from
Bhagavad Gita 1.40 When a dynasty is destroyed, its traditions get
vanquished, and the rest of the family becomes involved in irreligion.
Bhagavad Gita 1.41 With the preponderance of vice, O Krishna, the
women of the family become immoral; and from the immorality of women,
O descendent of Vrishni, unwanted progeny are born.
Bhagavad Gita 1.42 An increase in unwanted children results in hellish
life both for the family and for those who destroy the family.
Deprived of the sacrificial offerings, the ancestors of such corrupt
families also fall.
Bhagavad Gita 1.43 Through the evil deeds of those who destroy the
family tradition and thus give rise to unwanted progeny, a variety of
social and family welfare activities are ruined.
Mahabharata 13: Anusasana Parva SECTION XLVIII
Thus to these mixed castes spring up from improper and sinful union of
fathers and mothers belonging to different castes. Whether they live
in concealment or openly, they should be known by their occupations.
The duties have been laid down in the scriptures for only the four
principal orders. As regards the others the scriptures are entirely
silent. Among all the orders, the members of those castes that have no
duties assigned to them by the scriptures, need have no fears as to
what they do (to earn their livelihood). Persons unaccustomed to the
performance or for whom sacrifices have not been laid down, and who
are deprived of the company and the instructions of the righteous
whether numbered among the four principal orders or out of their pale,
by uniting themselves with women of other castes, led not by
considerations of righteousness but by uncontrolled lust, cause
numerous mixed castes to come into existence whose occupations and
abodes depend on the circumstances connected with the irregular unions
to which they owe their origin.
But knower of Brahman alone is a true Brahmin, not by birth alone as highlighted by modern yogis, Swamis, Paramhansas and social reformers of Hinduism of 20th century like explained in stories of Satyakama Jabala and Vishvamitra. The mixed varnas are not untouchables but random genes and gunas, even Adi Shankaracharya, founder of 4 Mathas of Hinduism and propagator of Uttara Mimamsa Vedanta had to learn final lesson of Brahm gyan from a Chandala and touched his feet in Kashi before realizing Brahman perfectly.
Some of the rules of eugenics, which is spiritual science, not scientific cloning or GMOs are mentioned in Brihadaranyaka Upanishad and Garuda Purana
7-10. After menstruation the women should be avoided for four days.
Their face should not be seen during that time, lest sin should arise
in the body.
Having bathed, and washed her clothes, a woman becomes pure on the
fourth day. From the seventh day she becomes fit to perform the rites
of worship to the forefathers and the Shining Ones. During the seven
days the embryo continues impure. Here the sons gradually enter during
the eighth day. Sons are born on even nights, daughters on odd.
Keeping away from, her during the first seven days, on even nights he
11-12. Sixteen nights are declared to be common for women. 1 On the
fourteenth night the seed remains there certainly. Then is produced
the righteous son, a store of auspicious qualities. That night is
never obtained by vulgar people.
- On the firth. day women should eat sweet foods. Pungent, acid, astringent and hot things should be entirely avoided.
14-18. The husband, like a husbandman, having sown the seed of great
potentiality in the field which is productive of grain, reaps a good
The man, having chewed betel, 1 put on flowers and sandal-paste, and
clean clothes, and with righteous thoughts in his mind, should unite
with his good wife. According to the thoughts in his mind at the time
of union will be the nature of the one who enters the womb. The
intelligence joined with the seed remains always in the sperm, When
desire, thought and sperm become united, Then the man obtains semen,
and in the interior of the womb the formation of ovum takes place, by
the union of sperm and germ
- The good son who enters the womb is the giver of the highest bliss. For him there are numerous rites, such as the Punsavana.
The above eugenics is also explained in a story of Markendaya Purana of Varuthini, sage Pravara and Kali and in Mahabharata during birth of Pandu and Drihtrashtra.