I started another thread, about the possibility of a FB/40K crossover caused by this end times. That is in terms of fluff and rules.
Now people have stated that the warhammer world is a planet somewhere in the 40K galaxy and that that fact has been mentioned in fluff - I have never seen that.
But, one person posted an interesting comment.
Slaanesh is about.
So that must mean on a time line, either the 2 universes are completely different, or, the Warhammer World is doing its thang well after the fall of the eldar.
So the question for me is:
Whereabouts in the 40K galaxy could the warhammer world be?
Personally I think the Eye of Terror is too easy - but this needs to be somewhere that was close enough to exodite worlds, squat homeworlds and an ork incursion, to allow ships of those races at a low tech level, to get there (bearing in mind there is absolutely no examples of higher tech - there are black powder level planets in the Imperium but the governor and mebbe the odd arbites will have higher tech in reserve just in case.)