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
Time delay not a good solution, because you're just delaying the heavy alpha strike wipe damage to a later point.