Wagner's command is competent. The recent border incursions show Russia is lightly fortified, possibly Moscow, too. The wild card would appear to be the FSB. Do they tend ultranationalist? Or will they be loyal to Shoigu?
The best way to ensure his own safety at this point is a coup.
He still may think that gives him better odds than not attempting the coup does, under current conditions...
But it remains to be seen whether or not Prigozhin would try to topple Putin or merely the army leadership in order to put himself in command of the war. The video statement I saw him make [1] would suggest he’s intending to gain control of Putin but keep him as a figurehead.
These took months if not years to prepare, even with domestic ones.