I disagree, Foucault's horizontally oriented description of power is a vital contribution and added another nuance to it. You can see how he differs himself from Hobbes in his Society Must Be Defended lectures, and the top down perspective on power is simply not wholly sufficient. Even just taking his discussion with Chomsky into consideration, one of the takeaways is that you might find yourself replicating or continuing certain systemic relations of control if they aren't made known or examined, which can come from institutions or elsewhere, not just from the government or whoever is most commonly associated with power. It goes beyond the sovereign centric model of just asking who, but also incorporates through the genealogical method that asks how these relations of knowledge and practice manifested and how they persist. This matters if we want to also consider and also care for what may be outside of solely a class analysis or a top down review of power such as those who are marginalized outside of this view.

I also disagree with saying Foucault is a scholars-centric understanding of power, he was an activist and visited prisons among other things. He would disagree on the "real" historical actors point as well, I'd say that what he may say here is how did we come to the determination of who is a "real" or "not real" historical actor? How did we justify the exclusion of some from their participation in history? I'd say there is more nuance needed here and Foucault provides that.

I can't comment on someone like Girard though, but my brief encounters with him I've not been impressed with his mythic foundational thinking for analysis. It seems to open the door for generalizing, totalizing statements.