This is true. Part of why I harp on Hanse choosing to go after the Confederation in the 4th SW being a mistake. The Elsies accomplished a lot basically on their own, imagine if Hanse hadn't passed up the chance to finally wage a coordinate squeeze-play campaign against his and House Steiner's most hated enemy and to seek personal revenge against Max Liao instead.
We always forget the externalities and other conditions that influence the decision making. The CapCon tried to sponsor a coup inside the Fedsuns, and did so via the Hasek-Davion branch of Hanse's over-sized family.
he kinda
had to do something about that, the FedSuns looks, at surface, like a monolith, but it's got a history as rife with civil wars as the worst of the Free Worlds League, only those civil wars are family fights...as in fights between members of the Davion family, the FedSuns is less centralized than it might first appear as well-there's only so long Hanse could sit on the Haseks or the Sandovals before they become a threat to his rule.
IOW domestic politics may have had as much to do with the 4th Succession War, as anything Mad Max did, and influenced the war of '39 as well.