If you're playing on the harder difficulty settings, Total War: Warhammer 2 offers a bit of a strange experience. You are heavily limited on how many armies you can field due to increasing costs, while the AI is able to spew out nearly endless waves of elite troops. As such, your only real recourse is to forgo basic units entirely and make all of your armies as elite and deadly as humanly possible.
Obviously, this isn't exactly ideal as campaigns quickly tend to become very samey, which is why Creative Assembly have now released the experimental Proving Grounds update into beta testing. To put it simply, the Proving Grounds update drastically changes everything from campaign balance to unit recruitment and difficulty, all in an effort to spice up the campaign experience as a whole.
Recruitment and building costs have gone up in order to encourage careful planning, while the Supply Lines penalty that makes subsequent armies more expensive has been removed entirely. Public order and growth buildings have also been retooled to be more effective, at the cost of the settlement buildings themselves no longer offering free bonuses. This should still make it possible to control and grow many provinces, but you will no longer be able to do so as quickly or as cheaply.
I can only hope this will also reduce the seemingly endless tide of Order-aligned forces
The goal behind these changes is to push end-game and elite units later into the game for both the player and AI, as well as create more varied campaigns where you never really know which AI empire will rise to the top. As an added bonus, this also makes those early-mid game units a lot more viable, while also ensuring that every elite unit you have is all the more special throughout the beginning portions of the campaign.
You can also expect to see changes to the difficulty settings themselves. Easy difficulty has been added to help players that are completely new to Total War, while the previous Normal difficulty has been retooled towards fast campaigns with cheaper recruitment and construction. What used to be Hard difficulty has now been relabeled as Standard, and represents a classic, slower-paced campaign with more expensive recruitment and construction options. Veteran (formerly Very Hard) and Legendary, on the other hand, are pretty much the same as they are now.
There is a lot to unpack here, so if you're curious about the Proving Grounds update, you should head on over to the official website to learn more. Have fun with the beta, it really does seem to be an exciting update!