Ignoring the obvious [the writers' desire to end the Shinou League in just one episode], I think Satoshi made several mistakes when he chose his line-up. He never should've brought Fukamaru and Cotoise to that battle. Fukamaru's only real claims up to that point was its Draco Meteor attack and the fact that it could use Rock Smash: the latter attack which Darkrai recovered from quite easily, anyway. Draco Meteor in itself wasn't a particularly useful attack again fast opponents from my viewpoint, so that wasn't a good strategy either. Then there's the simple fact that Fukamaru just wasn't bulky enough to have good defensive properties, as witnessed when it lost to a single Dark Pulse. As for Cotoise, it never had any impressive wins up to that point, so it really should've been left out due to common sense alone.
Even Heracross was quite middling in general: it didn't have the most impressive battle record, so it shouldn't have been on Satoshi's priority list as a good weapon against Takuto, but this is assuming that Satoshi put any real thought into his choices to begin with, which I'm not certain we're meant to believe he did. The rest of his choices were decent, although I question why Pikachu was capable of battling while Goukazaru, Mukuhawk, and the others on his main DP team were apparently out of commission. In general however, Takuto outclassed Satoshi in almost all respects.