AD comp vs AP/Tank comp?

It came to 40 mins where we had a farmed Nasus but we were against a fed Ziggs. I was Kalista and it was nearly impossible to teamfight against Ashe, Bard, Dr. Mundo, and Nautilus (just clicks R) and I had to backout.

Post game lobby I had Rengar "complaining" to me about my build saying lifesteal would help. I agree Bloodthirster/Botrk might have been more suitable as a first buy but would have it made any difference against this enemy team seeing how we had no AP late game? It was either win early by the 20 min mark or get suppressed by them late game: we couldn't get Mundo out of our faces and Ashe/Ziggs just zoned us to death while cc from Nautilus and Bard just kept us from running/engaging.