They don't mind some current ime, though it shouldn't be a whirlpool in there. In fact, I have an alpha male that spends half his time near a rock in front of a canister outlet. Contrary to popular assumptions, or what you see in some articles or hobbyist sources, the lake is not dead still at frontosa depth, but has a variety of upwellings, internal waves, turbulence, and currents, driven by complex wind patterns, internal convection, etc. So they're not going to want a whirlpool, but they're not the absolute still water fish some people make them out to be.
IMO, though, you do want some quiet areas in the tank, somewhat protected from water current, especially for spawning purposes.
Sample reference:
Lake Tang circulation (click the "more" link in the article for more text)
If you wanted to find your own references you can search on such terms as: Lake Tanganyika-- hydrodynamics or limnology or seiches or circulation, etc.
