PPSh-41 should not be a doctrinal upgrade, it should be an alternative upgrade for the 7th person. Also, to be an "assault package" when purchasing a PPSh-41, Molotov must be replaced with RGD-33 / RG-42. DP-27 replaces the PPSh-41 in commanding ability.
That's an idea many people stood behind, but I doubt it would be implemented despite the fact that ALL other SMG upgraded units get an ability to go with the theme with exception for rangers, but they have their own unique quirk with 3 weapon slots already.