Summoner getting ganged up on

[Kemiko]

Doing your class quests up to 50 should net you a coffer for i90 gear so you won't have anything below that. While it's not a fantastic solution it should help. Upgrading your gear across the board should also help but hitting an enemy with your Bio & Miasma and then spreading it to grouped up mobs should assist in quelling opponent numbers quicker before your HP depletes. Physick is a terrible healing spell in a Summoners hands so I wouldn't rely on it for anyone amount of healing.

Garuda is much more beneficial to use against groups of enemies where Ifrit is better suited to single target. Titan, however, should have some sort of defensive capabilities to grant you if you feel you need more survivability over offense. Also, Tri-Disaster is your aoe attack after spreading your bio & miasma though Ruin II will allow you to maintain mobility while dealing damage.

[Gruntler]

I mean, level 90 gear is 40 ilvls higher than the gear everyone had to do that quest in soooooo