Sherman 105 is the way for this Commander.
Yup, sherman 105 would be ideal here. Has bonus damage versus garrisons and increased protection, perfect unit for urban assault.
You know what else would be ideal in urban assault commander? Assault engineers. CQC squad with flamers and demo charges, perfect versus garrisons, emplacemants and low range urban fighting.
Some artillery to level area would be good too. Like for example 240mm howitzer barrage. Destroys buildings in huge area, forces enemies to leave garrisons.
And then you realize USF has perfectly viable urban assault commander, its called Armor Company and is stronger and more coherent than this new commander, which has no synergy between its abilities.
Ironically, USF lacks good armor commander, something like Armored Assault or this new ostheer commander.
And when it comes to calliope, Tactical Support has way better synergy, with recon overflight spotting for targets and p47 strafe keeping them in place. All it needs is decrese in cost for its abilities: recon overflight from 80 to 60 muni and p47 strafe from 125 to 60 muni, excatly the same cost as ostheer abilities.