Overall I think this was one of the best filler eps I've seen. It actually almost makes up for the useless crap...

Anyways, I think sending Naruto in alone was tactically unsound in traditional thinking, but the right choice. Even though he's not the greatest character, he has gotten considerably smarter as far as his individual actions. It was better for the rest of the team to fight together against the small fry as well since their combo techniques require almost the whole group to counter.

Now, playing into the lone star stuff... consider that if the enemy was as dangerous as the team suspected, and Naruto was injured to the point where he was forced into Kyuubi mode, it is much safer for all of them if the team stays away from him.