As mentioned I've played a ton of the older games of Medieval II and Rome I. I dabbled briefly in Warhammer and just put maybe 30 hours into Attila. Wow the game is so much more complex and unique.

Adding all these layers of control, fertility, loyalty, intrigue. It's so a more complex game! Before it was just economic and militaristic. Now there's politics and such. Also idk this is just Attila or what but diplomacy is much more complex and seemingly realistic! Alliances and treaties seem to hold more weight. In old games alliances just worked until they decided to attacked you. Playing as the Ostrogoths, and by consistently attacking the romans almost all other factions support me. I ran into money issues briefly and they all agreed to fund me to continue my war efforts. I found myself so immersed into the game.

TLDR: I played Attila after a long time of player older TW games and I'm blown away by how far they have come from already awesome games. Can't wait to dive into Warhammer at some point.