These vehicles weren't tanks as such but sort of a 'heavy organic infantry support' vehicle. They were supposed to be parceled out to each infantry company, for various reasons the French would not be able to mechanise all their infantry divisions, and overwhelm the enemy's infantry positions. Tank fighting was the job of the S35s, Char Bs and the tank that was supposed to equip the French armour divisions¹.The two I'm having a problem with aren't going to fix their core deficiency no matter what I upgrade. They start with their best penetration shell, but it's just grossly inadequate.
So while it looks like a tank it definitely isn't one.
I like them because they're funky little things but they really shouldn't be fighting other tanks
(1) If the Germans had screwed around and given the French a chance to raise their armour divisions it would have been a very different war