As scholar & warrior main (lvl 35 atm, sniff) i would go with summoner. The utility is real.
You can insta ress the tank if things go south as a DPS class(!).
You can summon your own tank (Titan).
You have a heal (physick).
In movement heavy fights you're really well off since 2 out of 3 damage sources you have don't require you to stand still all the time (pet attacks & DoTs).