Combination of things...
Knocking one guy out of stock for winning is just a short term slap on the wrist. Alone it does not make much sense. If ROAR wants to make Stock a Novice class then you should have to prove your Novice status. Example: No major event top three finishes, No team drivers, etc.
I think Stock is the Sportsman class. There should be no need to have two stock races at national or local races. All other kinds of races have support classes along with the main event races. Stock should be a support race at the national races, with the main events being 19t and Mod.
Back home at your local track the fast guys would be practicing for their main event races and the new guys would be learning to race in the stock class. The new guys can also get a chance to race at a National event against other new guys in the Stock class. If they do well and place in the top three, then they should loose their Novice status.
Slowing down Stock is also a great way to make it cheaper to race (less broken parts). Keeping is BL/Lipo would also make it cheaper to race and easier learn too.