Adisankara himself confirmed that he is vishnu.He had done both stotrams of Kesadi padam and padadi kesam for Venkateswara. Generally one is done for male gods and another is for female gods. ( forgot which is for which).Intrestingly the tamilnadu is vengadam mudal kumari varai. see both the pictures.
Botyh the Gods of Vengadam and Kumari have
1. Two hands ( for Balaji the changam and chakram are metal attachments)
2. Both keep the left hand in a simillar position.
3. The right hand position is almost simillar. balaji showing his feet as the destination for salvation and Kanyakumari, keeping her japa mala
4. Balaji wears 18 yord saree as doti.
5. balaji has both jata magudam and long hair ( Thazh sadaiyum neel mudiyum)
Confirming both are the two manifestation of the same. ( Ariyallal Devi illai) - The one which cannot be separated from siva is sakthi and sakthi is the other form of narayanan - paramacharya.