Is there a difference in them between the 2wd and 4wd?

Reason i ask is that my 2wd sump looks to have a circular mark in the bottom of it from the pickup pipe. (sorry no pic a present).
So my pickup must be VERY VERY close to the base of the sump, to the point where i would have thought it would restrict flow and potentially sunction to the bottom.

Do 4wd pickups go deeper? Thinking i may have the incorrect one..

thanks