Arty commander is useless? In team games its solid. The val suck donkey dick by frontline wide flares is beyond strong, and with a price reduction the overwatch arty would be incredible.
Seriously, make the val ~ a stuart and swap its arty ability with recon and it would solve alot of problems (make it come earlier too obviously) and it give a light vehicle option that isnt the AEC.
Maybe give the sexton airbust with anvil or vet too to jaz it up
Priest: 180 Range, AOE near with 200 damage at range 2.0
Sexton: 135 Range, AOE near with 160 damage at range 1.5
2.0 radius nearly doubles the area that is hit with full damage and that will do the squad wipes, this is a huge difference. Range 180 to 135 is a huge difference too, especially when you want to shoot at that stationary howitzers build near base with 250 range. You won't reach them with a Sexton. All of that for the small difference of 30MP, 15 fuel and one population. It doesn't matter that the Sexton has a little bit faster shooting cycle, the Priest does the damage versus crippled tanks and the squad wipes. So just always go for the priest. Yes, the airburst option would make a Sexton more versatile without copying the Priest and would be a good move to make it unique and more useful in one go.
Second problem of the artillery commander is the Valentine, as you already stated. Comes way to late in that 3vs3 and 4vs4 because of ressource inflation. There are AT tanks around when it hits the battlefield so it has absolutely no AI shock value anymore and is hard to vet up. Artillery ability isn't that great, so its basically reduced to its map hack that OKW gets non-doctrinal with a smaller arc but a lot earlier and a lot cheaper (5 fuel to 80 fuel / 5 pop to 12 pop). Infrared truck is way better designed, Valentine just wastes it combat values if it is used as map hack only (and you want use it like that). It should be bind to tech and come when you either researched AEC or Bofors (or something like that).
The offmap flares are quite good in that large battles, the two offmap barrage abilities are just okay. So current performance of Sexton and Valentine ruin this commander for me.