Another detail ....
Remember that another component of a 'starter' is the contactor. I can think of no code requirement for there to be any manner of contactor; the use of full-power rated switches and plugs is allowed.
If you had 'heaters' but no contactor, you would not have a 'starter.'
Lest some newcomer try to read something into my comments that I'm not saying, I'll be the first to extoll the advantages of using a contactor; that's another discussion.
