1. Beastlord has 2 problems. {A} Beasts can start out very overpowered and take down dragons with ease, especially Cave Bears. If they aren't exploited quickly, they can obsolete fast, so you are forced to "use or lose". {B}. Beasts have no upkeep costs, and don't have any animal armors. They also don't gain useful abilities, and after a while just feel like "tamed units" instead of "Beasts". There aren't Beast abilities that they get over time which make beasts meaningful as succinctly being a beast.
2. Units level up extremely slow. Even with every exp buff in the game, it takes a while to get a good army. Meanwhile, leveling them up feels minimal in improvement versus waiting 3 techs and building a new unit.
3. Mounted Combat is not fun because it is a forced maneuver. The moment I have access to them, its "Pawn to King 4...". The problem is that animal mounts are limited to Horse vs Warg and any nonmounted version of a mounted unit is worthless.
4. Too many abilities, even after patch notes, come in low intensity stages. Vital Strike and Potential are great examples. I propose that potential1, potential2, and potential3 are removed. Also, remove Trainer 1, 2, 3, 4. Instead, place 2 potential skills with 15% and 25%, and 2 trainer skills with 15% and 20%.
5. Too many spells have little to no effect because they have a small base number + x for shards. This looks good until you realize out of 20 abilities on a unit, only 3 of them do above 6 damage when your level 20.
6. Fix the Unit Design Double Equipment Bug. When you design a Henchmen with 4 accessories, you can purchase and equip 4 more artifacts, which by all appearances, are "invisible in the background", and "stack" the new and old ones together.
7. Champions should have a "choose later" feature, and you should get a board of like 20 champions for your race/faction, and spend Fame to get them. You could also have a system of selecting specific upgrades for Champions instead of a new one. That would be fun, to make my heroes legendary instead of always recruiting heroes worse than units just to steal their spirit.