The way you beat iruka teams is you break the combo and you never focus iruka. Since iruka is generally a defensive ninja slot - if they're also running a healer u're very likely to have much higher DPS than your opponent and if not then you might have to consider looking for a different lineup.

Gaara karin and hinata is a very very stall-y set up... In fact the only way I see you winning is poison damage. While your opponent on the other had had a Sasuke which gave him the edge in the fight. I would consider dropping either Gaara or Hinata in your lineup for a damage dealer.