I feel like button with the AT rocket strafe would be too good, you already get good value sacrificing a T-34 ram with it.
40 munitions instead of 300mp and 90fuel would be a complete steal.
Give the DP guards "Fire superiority" since it synergizes better with them, and give the PPSH guards sprint- or a "Reload" ability which would force a reload and readies them for the next engagement. The potential for such an ability is quite good.
40mu ontop of the 90(?) for the upgrade ontop of the at strafe. It's cheaper on paper, but more expensive in the sense it's competing for the same resources in a commander that also has SVTs which are great. All about economy my dude.