I always figured the “Punch” personality would be the one to defect to the decepticons while Counterpunch stayed loyal to the Autobots (out of hatred for his decepticon coworkers and being the best way to ensure them harm)

Or Punch develops a “true” (as in delusion-based) alternate personality born from his fears in contrast to  the intentionally programmed Counterpunch.

I mean, Counterpunch hates everyone sure, but that also describes quite a few autobots. And he likely hates the dcepticons more, just like those autobots.

Making Counterpunch a generic “evil side” just seems kinda weird and wasteful.