[saudioger]

I assumed that they really just didn't communicate with each other well. Leia showed up on her own (and failed), Luke sent the droids as part of _his_ plan (also failed), Lando was trying to get Han out from the inside (interrupted by the other plans)... they just didn't coordinate.

[cgriswald]

At the end of ESB, Luke and Leia are together with the droids in the medical frigate, while Lando and Chewie are together in the Falcon. They have plans to meet on Tatooine to rescue Han. It would be surprising if, after meeting on Tatooine, they all went their separate ways to try their own plans.

[protomyth]

Yeah, it was one scene away from all those older heist movies where everything went wrong because everyone was trying their own play at the same time. It really seemed like everyone went their separate ways.