We might give the upgrade a manpower / fuel cost instead of munitions partly because of this and partly because the commander is already very munitions heavy. That will put the cost at OKW P4 level, which matches its new performance.
No it is superior to Panzer H and OKW PzIV.
Similar armor, more HP better AI and better AT. I would argue it more cost efficient than Dozer also especially with the WP rounds.
Simply replace with Dozer.