ifrit's burning strike plus auto attack is about even if not slightly more damage than garuda's wind blade.
Haven't tested this since 2.4 or so but If you count ifrit's attacks you will see his autoattacks are faster that his burning strike. I think it was about every 6 burning strikes he would do 7 autos (maybe double that, it's been to long). That's how he ends up surpassing garuda over time assuming minimum movement so he gets the uptime to get those extra autos