This translation is provided by Griffit,an alternate translation is provided by HH wilson according to Sayana.They are -
when thy(younger brother) Visnu by(his)strength stepped his three paces,then verily thy beloved horses bore thee.(Rig Veda 8:12:27)
The following verse from Rig Veda renders the above translation by wilson more probale.
Wilson also offers alternate translation for Rig veda 10:113:2
visnu offering the portion of soma,glorifies by his own vigor that greatness of his.Indra the Lord of wealth,with the associated gods having slain Vritra become deserving of honour.(Rig Veda 10:113:2)
The verse glorifies visnu as one who is glorified by his own strenght,while Indra become deserving of honour after having slain vritra only in assocation with other gods.
However visnu praising other gods need not to be taken as worship.wilson translate
visnu the might giver of dwellings praises thee,and mitra and varuna;the company of maruts immitates thee in exhilaration.(Rig veda 8:15:9)
the following verses show vishnu as distuinguished from other Gods IN Rig veda.
he who presents(offering) to visnu,the ancient,the creator,the recent,the self born;he who celebrates the great birth of the mighty one;he verily possessed of abundance,attains the(station)that is to be sought by(all ).(Rig Veda 1:156:2)
no being that is or that has been born,divine visnu,has attained the utmost limit of thy magnitude,by which thou hast upheld the vast and beautifull heaven,and sustained the eastern horizon of earth(Rig Veda 7:99:2)
These all translations are provided by HH wilson while according to griffit Translation Lord vishnu extols and lauds Indra deva s majesty