I'm not sure about that. If a Rep wins his primary this year by 80-20 against anyone, then any future opponent will be discouraged. If he wins against his generic opponent by 55-45, then an opponent will have more opportunity to raise money and build support. No one likes to throw money away on someone who will likely lose 80-20 in a primary.
This is something you’ve obviously given a lot of thought to, but the entire premise is built on your assumptions of what will/might happen.
Referring to earlier posts in this thread, the primary is not the time to experiment with election theories.
I support your conservative views, but I’d encourage you to vote for the most electable candidate in the general elections—absent other policy reasons, of course.