Take for example:
Giving partisans sprint+fast decap would emphasize a role of disrupting enemy lines or giving them ambush camouflage+reinforce from ambient building and less reinforcement costs emphasizes a long lasting ambush unit.
We've tried that in WFA alpha with JLI. It was broken OP.
Reinforce from ambient buildings makes more sense, but it doesn't matter where you can reinforce from if you have models expensive as grenadiers with combat capability of default weapon crew.
I don't necessarily think that they shouldn't be compared stat wise with Osttruppen both have different roles to play, they just need a clear role to play and give them the tools to make it happen. As of now just spawning out of ambient buildings is not enough but with some tweaks (and new abilities) they could be really good in the right hands.
Its infantry that doesn't scale, doesn't have impact, the only good thing going for them, molo, was nerfed making them even worse against weapon teams and they could barely stand up to pios, osttruppen mop the floor with them.
Its infantry that exists for the sake of different looking combat engies that plant wire and mines.