I think the Promotions that give melee Units more Combat Strength when attacking Cities are too weak. Currently Drill 1, Drill 2, and Drill 3 each give you +25% Combat Strength when attacking Cities. City Assault gives you +50% Combat Strength when attacking Cities. I think to make attacking Cities with melee Units viable the values on the above Promotions would have to be changed as follows: Drill 1/2/3: 25% CS -> 35% CS. City Assault: 50% CS -> 100% CS. I recently played a game where I increase the CS percentage bonus against Cities from Drill to 33/33/34. It made attacking Cities with melee Units worthwhile in some circumstances but it still felt a little on the weak side. (I was taking Drill 1 -> Drill 2 -> Drill 3 -> Stalwart on all of my melee Units.) The reason why I think City Assault should be buffed so much is that the circumstances under which it gives you any bonuses at all are relatively limited. If you're in a position where you can freely attack a City with your melee Units you can usually also just attack it with your siege Units. For reference, the equivalent Promotion for melee naval Units also gives +100% Combat Strength when attacking Cities and I think the benefits of that Promotion are about right.