I mention this only so you won't think I'm reacting personally when I make the following statements:
1. Blood Bowl is already based in part on WHFB, so I'm not sure why someone would say he wanted this line cut. If there was no WHFB, there'd be no BB; there'd be no Gutter Runners, no Troll Slayers, no current configuration of Undead on the same field of battle. Instead, there'd be Throwers, Blitzers, Runners, Catchers, and Linemen, and occasional cries of "Please import some WH positions into Blood Bowl!"
2. Assume for a moment that these rosters are balanced and playable. (Big assumption for some of you, but bear with me for a moment.) If these had been the starting rosters 8 years ago and they had suddenly been collapsed into a "unified Undead," I wouldn't be reading about how GW shouldn't split the teams up; I'd be reading about how they shouldn't unify them!
Just think about those last two points for a moment. Then take your new Undead toys out for a spin

(I know I will. And yes, Regenerate on the Golem would be better than Stand Firm.)
Cheers.
-Chet