I like Gaara, but I believe Deidara was at a bigger disadvantage than Gaara in that fight. He had limited clay, and his mission was to capture Gaara, not kill him. It's a lot harder to capture someone than to kill them, especially someone like Gaara. Deidara won that fair and square.Gaara and Shino. Hidan can't touch either Gaara or Shino since they are long range defensive fighters. Which basically makes this a Deidara vs Gaara and Shino fight.
Gaara would have beaten Deidara if deidara didn't attack the village. gaara let his guard down only to protect his village.