all the fighting fantasy stuff totally influenced warhammer. Even the old world has many similarities to titan the FF game world. Their background book had the best write up on orcs ever.
Well... early WFB and 40K are really a mish-mash of... ahhem... homages. If you're familiar with UK F/SF scene in the 70-80's (especially 2000AD), it's kinda weird fun playing "Where did they borrow this from?" with Warhammer fluff. Like going over the Space Marine implants etc. and comparing that to the stuff a G.I. trooper has -- pretty much the only thing they didn't take is the blue skin.
I say early because I really haven't kept up to date with it in ages. I hope more money has b(r)ought more originality, but probably not.
Part of the same imagery is explained by actually using the same artists, and I really can't fault them for that.
Before anyone gets all huffed and puffed about this: Culture is always built on existing culture and nothing is created in a vacuum. But there's also acknowledging your roots, giving credit where credit is due. The line between homage and plagiarism is a thin one, and mostly created by admitting the fact.