He's really not a support class. He just has the ability to build teleporters, which happens to belong to a support plant as well.
Engineer is the Zombie parallel of Peashooter, not Rose. (Aside from the teleporter building)
He has:
-Splash damage primary which I believe almost exactly parallels the Peashooter's
-A grenade that stuns enemies rather than dealing damage like the chili bean bomb
-A turret ability, slightly different from the Gatling Pea
-The Jackhammer, which is basically just a more horizontally focused version of Hyper
Not saying they're balanced, but you should be comparing him to another assault character, especially when there is one who mirrors him so closely.
