Perks are one thing, as they are set up before the battle, and don’t change during the fight. Changing like they do through your suggestion would just result in an OP mess, most likely with assaulters and flamethrower troops running through with even MORE health and speed. That is NOT what is needed.
I imagine it wouldn’t stack if you already had those perks…just complement ones you didn’t (sorta a teamwork orientated stopgap between new players and vets. Just spitballing.