huh, Krazy brings up some tactical points that really do make you question Sergei's "brilliance". It's clear that he's trying to capture the Gundams... but you would think destroying the Ptolemaios would be part of that...
but, now that I think about it, you may be right when you say all we saw in this episode is Sergei's own diversion... holding back the Ptolemaios (no way that he knew they didn't have any serious firepower on the ship... in fact, you'd almost have to assume that a ship belonging to a group as technologically advanced as CB would fuck your day up...) while trying to capture the Virtue or Kyrios (the airplane looking one).
Either way, one thing is clear, and that's that Sergei is spreading his forces to engage all the Gundams at once. This seems absurdly risky. I understand that you need to keep the Gundams from ganging up on you, and his strategy certainly keeps them relatively isolated and avoids getting flanked by the Kyrios and Virtue...
You'd assume they'd leave the Exia (clearly an anti-mobile suit Gundam) and Kyrios (fast enough to probably escape no matter what) and go for the slow Virtue or the Dynames. Both of those units seem to be weaker in close combat. They're both hard to get at initially because of their incredible range, but once you swarm them...