The problem with current CA/SEGA approach to TW is they try to release a new game every year now, and release as many DLC as they can per title, whatever the cost to development quality and credibility.
IMO its a cash out strategy.
I can imagine the devoted developers working their ass out just so that they meet the deadline, knowing full well that they can not give their best shot with that they are given. Still, Rome 2->Attila->Warhammer shares tons of similar assets/UI/gameplay/etc... so with each new titles they can get deeper into the strategy/politics/battle aspect. Like with Empire->Napoleon->Shogun 2.
But that also means we pay 3-4x a AAA game to have an incredible experience.
Unlike Empire->Napoleon->Shogun 2, where Shogun 2 was basically a masterpiece (ignoring design flaws due to cultural similarities between all the playable factions), Rome 2->Attila->Warhammer, where Warhammer could be the masterpiece of the cycle, I dont see as much "innovative" gameplay decision: they have announced that the multiplayer of Warhammer will be the same than Rome 2/Attila (no great tools for multiplayer campaign, no avatar multiplayer), they showed that there is no real "lore" exploitation of the Warhammer history ("heroes" are just buffs, factions starts with ridiculous positions lore-wise and stupid neighbouring rebels/neutral factions just like any other TW, "quests" are simply finding more buffs, most of the lore is just text printed on ultra classic gameplay), and one can already see that graphically wise we are going to have problems, rosters are a bit limited and pasty, factions are DLC locked, etc etc...
Still I believe that overall, Warhammer should be >>> to Rome 2 and at least > to Attila.