Sturmtiger used to be stock unit.
The Elite Armor was improved greatly.
HEAT was always a great ability, ST is still a very potent unit, 221 is interesting addition giving another light option with utility for early game, worst thing about the doctrine, tank commander barrage was buffed(delay made it completely useless prior to that) and emergency repairs got a massive buff as well.
You however seem to be completely missing the point of commander.
Its -NOT- supposed to give you super tank. Its supposed to make your armor less dependent of your infantry and increase their potency, which it does.
I'm not going to talk about overwatch, because I never played with it a lot, its goliath only for me from that doc.
Now you suddenly know what is "the point" of the commander.
Enlighten us then...what the hell is the point of kv2 siege gun in Urban Defense doctrine, and SHOCKtroopers ?