We have 12 Adityas of whom one is Vishnu. And 11 Rudras of whom one is Shankara.
Are they Vishnu and Shiva counted in Trinity? If not, who are they? Are they related to trinity gods?
Vishnu among Adityas is actually Lord Vishnu's incarnation Vamana. Sri Vallabhacharya, Sri Madhusudhana Saraswati, Swami Ramsukhdas, Sri Neelkanth and Sri Dhanpati translate the BG10.21 verse आदित्यानामहं विष्णु as Vamana. More details can be found here and in the below post:
Rudra is also an incarnation of Lord Shiva as the son of Lord Brahma, this is discussed in below posts: