*While in the manga, such chapter also left the impression that Sune could have done much more against an invader, it wasn't that bad for a reason:
The fight didn't last much there.
And for a good reason
-which clearly, the anime team didn't get- It is
supposed to be quick and brutal.
It's meant to show that while non invincible (Deidara loose an arm), such organization is force to reckoned. And that they are now really on the move.
If they can break through the vigilance of a whole Shinobi village and defeat a grown up Gaara -with Shukaku- and in his territory, then things are getting extremely dangerous for everyone. But again, all that dragging just weakened the effect. Almost as if Gaara could have had a chance when in reality, it wasn't the case. At all.
*Other problem is, that they added some scenes from the Sune village that will definitively reduce the impact of an event, later on the story.
Basically, they are just shown stuff from Sune's situation, that it wasn't meant to be even hinted yet. Bad, too bad.
*Plus, all that stuff of Tsunade sending Naruto to irrelevant missions is quite illogical, considering that he and Sakura just passed an exam that set them on a more equal ground to a Jounin.
Not only would also conflict with Jiraya's plans for him, it's also pointless: why allowing him to train with a Sannin for almost 3 years, if when he comes back, you just sent him away to do basic missions, but now also dragging your best medical student and a full Jounin?
It's like the whole Oro/Sasuke/Akatsuki/reconstruction /rival villages stuff no longer mattered. Rather poor.