One is that, although Thucydides can be fleshed out with some supplemental sources, he is far and away our best source on the coup and its defeat. I have cited Aristotle and Diodorus Siculus on the coup. Here is Diodorus on the coup failure:
At this time the Athenians dissolved the oligarchy of the Four Hundred and formed the constitution of the government from the citizens at large. The author of all these changes was Theramenes, a man who was orderly in his manner of life and was reputed to surpass all others in judgement; for he was the only person to advise the recall from exile of Alcibiades, through whom the Athenians recovered themselves, and since he was the author of many other measures for the benefit of his country, he was the recipient of no small approbation.While it is certainly true that Theramenes paid no penalty for his role in the oligarchy of the 400 and went on to be an admiral in the fleet, it also seems a reasonable bet that he role as a member of the 400 caused many to look upon him with suspicion.
Aristotle gives only slightly more detail:
The constitution of the Four Hundred lasted perhaps four months, for two of which Mnesilochus was archon, in the year of the archonship of Theopompus, who received the office for the remaining ten months. But when they had been worsted in the naval battle off Eretria and the whole of Euboea except Oreum had revolted, they were more distressed at the misfortune than by any previous disaster (for they were actually getting more support from Euboea than from Attica), and they dissolved the Four Hundred and handed over affairs to the Five Thousand that were on the armed roll, having passed by vote a resolution that no office should receive pay. The persons chiefly responsible for the dissolution were Aristocrates and Theramenes, who disapproved of the proceedings of the Four Hundred; for they did everything on their own responsibility and referred nothing to the Five Thousand. But Athens seems to have been well governed during this critical period, although a war was going on and the government was confined to the armed roll.Another is a general comment on the 5,000. Aristotle regards them as part of the real plan, which the 400 nonetheless failed to live up to. Thucydides, by contrast, regards them as so much window dressing. He sees this as a clever ploy, something that everyone felt compelled to give lip service to, even if no one actually wanted. He believed that the conspirators who called for instituting the 5,000 were simply speaking for public consumption and really were acting out of thwarted ambition. The hoplites who mutinied called for instituting the 5.000 instead of full democracy for fear of offending a neighbor who might secretly be one of the 5,000. Even Alcibiades, safe in Samos, told the representatives of the 400 that he could accept the 5,000.
Thucydides believed that the real purpose of the purported list of 5,000 eligible participants was to create the impression of a much larger conspiracy than actually existed, while at the same time preventing any conspiracies against the oligarchy, for fear that one of the co-conspirators might be one of the 5,000. Still, the plan had obvious drawbacks. A deception on that scale can only be concealed so long. Sooner or later, if the 400 never came out with the larger list, people would begin to suspect that it would never happen. Another drawback was that promising the enfranchise a non-existent list of 5,000 ultimately served to guarantee that all hoplites would ultimately prefer the democracy, since each would know that he personally was not on the list.
Even government of the hoplites, excluding the poor, had its problems. The most obvious one was the link between democracy and naval power. If Athens wanted to keep its overseas empire (and at the beginning, even the 400 hoped to preserve it), then it needed the goodwill of its sailors. Navies, it is true, cannot stage coups, but they can mutiny or desert, as the fleet at Samos made clear. It is interesting question whether the hoplites, given the choice, would have preferred a broad oligarchy based on the hoplites over full democracy. On domestic matters, no doubt they would have recognized that excluding the poor guaranteed they would swamp the rich in numbers and be the true rulers. But it would also have meant losing the goodwill of the navy and thereby losing their empire, or at least weakening it. Which would be more important to the hoplites? I suppose we will never know because it was not seriously tried.
Finally, it had to be addressed sooner or later, but what would the NRA and our general militia movement think of the whole thing? On the one hand, it emphasizes that a tyrant disarms the citizenry. Pesistratus disarmed the citizenry. So did the Thirty Tyrants, who we will see later. But that was not really an option for the 400, since there were hostile armies roving the countryside, and the city had to be closely guarded. And it is true that ultimately the army mutinied, marched on the city, and overthrew the oligarchy. It is also true that the navy deserted and made victory impossible without a return to the democracy.
But the NRA/insurrectionist/militia view has its shortcomings, too. For one thing, an armed populace most signally failed to stop the coup, even if it did later overthrow it. For another, both sides were very much opposed to an actual trial of force at a time when a hostile army was camped a few miles away, eager to take advantage of the city's weakness. For another, in Ancient Greece the logic of treating liberty as a thing for every man to defend with his gun (well, spear and shield) was not democracy, but oligarchy. A majority of citizens could not afford a spear, shield, or other such gear. They were, of course, the ones who served in the navy and won real political power by their military importance. But in the sort of armed showdown our insurrectionists envision, unarmed sailors would have been no match for armed hoplites.
But finally, and most significantly this, like most instances of paramilitaries, seriously undermines the basic insurrectionist paradigm. To the insurrectionist, the bad guys are basically government and the good guys are basically anyone outside of government. That dichotomy itself does not work so well in any government as diffuse as Athens.* But more to the point, the insurrectionist viewpoint assumes that the main threat to freedom is government overstepping its bounds, while private paramilitaries were necessarily champions of liberty. But in this case, if government had simply maintained its monopoly on force, liberty would have been safe. It was the political clubs and the "Hellenic youth" who served as their paramilitary that was the real threat to liberty.
And anyone who seriously examines the history of paramilitaries and private armies knows that that has been the usual rule throughout history.
*Granted, that leaves slaves, metics and women -- anyone who is not an eligible participant -- as being "outside of government."