FWIW, in an interview this year Tatiana Navka said the 3 teams who changed the sport in her opinion were P&G, T&D, and V&M.
Sadly there doesn't seem to be much footage of P&G or ice dance in general from before 1976. I would love to see what it looked like before and during their career to gauge how innovative they really were. I've seen people credit T&D for being the first dance team to use one piece of music straight through for an FD, but P&G did that as well with Masquerade Waltz. T&D did have a storyline though, while P&G's I think was just a waltz (but maybe there was some deep storyline reported in Russian media that we didn't know about). I think P&G get a little undervalued because of the lack of footage and English language resources about them. With T&D we already had a good idea of what ice dance looked like 8 years before them so we have a good sense of how it changed, and there were many documentaries made at the time in which they discussed their process in painstaking detail, as Dean loved to do. I think that contributes a lot to the perception that they invented modern ice dance. With that said, all of the Russian skaters also idolized T&D, so I'm not trying to suggest that their Anglo-ness is the only reason. It's just really hard to compare their innovations to P&G's.