Taking a page from the Siege of Tor Yvresse from The Warden and The Paunch DLC or the sieges from Thrones of Britannia or Attila would be a great step. Every battle basically plays out the exact same, on offense and defense, and with the number of sieges you have to fight, it really begs for a complete overhaul. They initially reworked sieges for Warhammer to be simpler for the AI, but all it did was infuriate the players and make them an absolute chore. Buggy interactions between climbing the walls and entering gates, having only one avenue to attack from, archer towers with ungodly range, AI that stands on the walls and gets bombarded with your artillery, magic users on flying mounts being able to solo entire battles, the whole experience is just a mess.
Sieges, as it currently stands, are not great, to say the least.
If you’ve played WH2, you saw this coming for our list of 5 features that should be in Warhammer III.