>>51736078Yeah, they were definitely a trio, even if there wasn't really much emphasis placed on that fact in Gen 1. The big thing that makes me suspect they were meant to be a trio even when they were first introduced is that, in Gen 1, the elemental punches were effectively their signature moves. They only shared them with Hitmonchan, who was explicitly a boxer, despite there being a few other candidates that could've gotten them (Raichu could've gotten Thunder Punch, for instance -- he got Mega Punch, after all).
Combined with stuff like
>>51736108 and
>>51736191, it seems pretty clear to me that GF always thought of them as a group to a small extent. I'd say it was only really formalized in Gen 2, though, and the controversy surrounding Jynx put a stop to that pretty quickly.