Everything that I've read so far says the "coup" you're referring to was a result of the Spartans after the Peloponnesian war. You haven't substantiated Socrates or Plato's involvement with any sources that even suggest that.
It's not at all like the civil war because it happened millennia ago with only fragmentary evidence. We have far more records from the civil war era due to it only having been a couple hundred years ago, which isn't that long in the grand scheme of things.
Aristotle was Alexander's tutor, yes, but Plato had no involvement with Alexander and the trial and execution of Socrates happened long before Alexander was even born. Plato and Aristotle are diametrically opposed philosophically, so bringing up Aristotle's involvement with Alexander has zero bearing on the philosophy of either Plato or Socrates.
Plus, the modern sciences owe far more to Aristotle than he's given credit for, so if tutoring Alexander the Great is such a demerit then we have to throw out basically all human inquiry that took place in the western world from medieval scholasticism to the modern scientific method. That would be a pretty severe ad hominem, but I guess if you're going that far then you'd have to throw out the field of logic too, so then you can commit all the fallacies you want because hey, the father of systemic logic tutored a Macedonian imperialist so all the fundamentals of logic must be flawed, right?