That's a good option. Partisans will require a cost recalibration regardless (they are definitely NOT worth 35MP per model); it's the dirt-cheap MP price that makes them an overkill.
Other alternatives are:
- Give a delay between issuing the infiltration command, and the squad actually spawning (say 20 seconds)
- Make the squad spawn with crap weapons, and they regain their default weapons after a delay has elapsed
I had this idea with delayed spawn also, but what if an enemy squad goes into the Building during these 20 sec? ^^