Ok I can understand that the buddy system was initially made for characters that had no transformations. I can completely understand where the idea originated from. I guess the way I'm looking at it from is more so comparative power. You said Piccolo was stronger than many saiyajins, and that's true, but is his max power level anything in comparison to SSJ2, 3, Kid Buu, Perfect Cell, etc? I suppose it's not a huge stretch to fill that gap with some minor bonus.
Teen Gohan could be a stand-alone character without a doubt, sure. He hit SSJ2 after all, which was the highest tier for the Cell saga. But in the Buu saga, he's an adult, and his teen character doesn't carry over. Again, in the max scheme of things, an initial SSJ2 isn't as strong as SSJ3, Kid Buu, Perfect Cell, etc. In Vegeta's case, he hit Majin.
I guess the biggest discrepency would be considering Trunks in this case and comparing him to Gohan. He didn't even make it to SSJ2, whereas Teen Gohan did. So this is really where untieing a knot in one place creates another one somewhere else.
Without a doubt Tien and Yamcha would be best under a buddy system with Krillin, but they're even weaker than the Ginyu Force. They'd be REALLY lame.
So okay, I can see how keeping Piccolo and Teen Gohan separate would be better for the whole roster. Having a Kid Gohan for the buddy system and keeping Teen Gohan separate would be out of the question since you'd have 3 Gohans now.
I guess the biggest set back I see is bringing Krillin up to par with even the Ginyu Force.
If the SAM went up faster fighting a higher PL character, then Krillin could be an extremely SAM bar based hero, and that might make up for it.
Anyhow, it was worth a shot considering it. Good feedback, thanks.