[Phlagm]

Well, i guess that's weird, but then again you wouldn't travel at the average speed of all your ships, either. YOu would travel at the speed of the slowest...unless you were towing them with the faster ships. In that case you'd need tractor beams between all the ships unless they had identical drives. I think it's best to just assume that they disengaged the tractor beam when they pulled up to the planet, because they were no longer travelling at a significant clip.