The problem with Nordstream conspiracies was in fact that you could easily finger anyone as responsible, absolutely including Putin. The benefit to Putin (not "Russia" per se) is that it eliminated the revenue source from gas sales to Europe in the immediate term, and thus made "end the war now" less attractive to his domestic power base (because it wouldn't make them any more money for a few years).

A coup from disaffected underlings unhappy with the status of the Ukraine war is hardly a weird theory. He's fought off one already!