Regardless of what you think, some percentage of those McCain voters are natural Republicans and could be persuaded to vote for Lake, you have to court them instead of telling them to get the hell out of your rallies.
No Republican including MAGA favorites can win unless they have unity among conservatives, neither side is capable of winning without the other.
Removing the last vestiges of the McCain machine in AZ is paramount to fixing the state GOP there. And as I said, you don’t invite saboteurs into your camp unless you’re suicidal.