But is the "Total War Warhammer" like a sub universe of the main Warhammer 40k universe ? I relatively recently got kinda deep into the lore ( i was blown away btw this sh** is MASSIVE! ) And i feel like they could add a lot more stuff!
I just want to command an army of Dreadnoughts already!
Oh no. Completely different universes.
The Warhammer franchise has three universes. Warhammer Fantasy, Age of Sigmar and Warhammer 40k. Warhammer Fantasy is a low fantasy setting, Age of Sigmar is high fantasy and Warhammer 40k is science fantasy though plenty folk argue that it is sci-fi. Total War: Warhammer is set in Warhammer Fantasy.
Warhammer Fantasy and Age of Sigmar are connected with the latter being a sequel to the former but 40k isn't connected with the other two.
Games Workshop doesn't do much crossover between 40k and the other two settings. Even the few things in common between the different verses like the Slann, the Old Ones, the Chaos Gods and a few named Greater Demons like Kairos, Skarbrand, Ku'gath and N'Kari, are treated as alternate universe versions of those characters.
So no, there won't be something like Dreadnoughts in a Warhammer Fantasy game. Games Workshop wouldn't allow it.