I definitely think Prigozhins “easiest” way to power would be to help the Ukrainians break through and encircle a large portion of the Russian army.

Rosguardia has hundreds of thousands of internal soldiers.

I may be very wrong, but I think that such a large proportion of the Russian armed forces and material are in Ukraine now, that if they were to be encircled and lose decisively (not that I think this is immediately likely) the Rosguardia would have a hard time. It doesn’t help to have hundreds of thousands of soldiers if you don’t have any heavy equipment, communication systems or command structure. Additionally, Prigozhin appears to be in good favour among quite a few Russians, so I wouldn’t bet against some of them joining him if he were to try something.

But given what you’re saying, the above seems like a pipe dream ^{but-I-want-to-dream-that-this-can-end-suddenly-and-quickly.}