Oh, well, that I agree with. I've really thought that even in ADV. That's why I usually take my teams to the extremes. If I'm making a stall team, I'm going to pick Knock Off over Earthquake every time, for instance. I basically start off with as few attacks as I think I can, and tweak from there. It really forces you to see what the flaws in a particular strategy is (in my case, Nasty Plotters), so you have to find a way around it.
I agree that the team itself isn't everything, but that execution plays a major part. The most obvious example of this is when you have to sacrifice something. A player that knows how to use the team will be paying attention to who the opponent has left, and sacrifice the Pokemon that is least needed. The player who isn't as good with the team will likely sacrifice the Pokemon they consider "weaker" or what have you. I may find my Salamence to be a lot stronger than Infernape, but if they have Weavile in the wings and a Camerupt that's about to Explode, I'm sacrificing Salamence.