Having given it some thought I have to side with the "it's anti GMT"-camp. I think we are underestimating the extent to which this show is self-conscious.
Note for example how the supposedly "brilliant" stratagems that the various characters use to win this or that battle are typically rather banal. You can put this away as lazy writing - the character is brilliant for the purpose of the story, but it is told in stead of shown.
However I started to notice how often, almost every time, there is always some character in the other camp who anticipates what is to come, points it out to the superiors, and is shot down. So clearly we are not dealing with uniquely
genius insights. Moreover the outcome of the battles is in almost all cases over-determined by the preceding circumstances. The most obvious case being the invasion of the Empire by the FPA really on - with no clear plan beyond "we'll be greeted as liberators" their defeat was assured before the invasion started, no genius opponents needed. Another case is the noble coalition, which falters more to its own internal tensions and weaknesses (factionalism and ill discipline mostly) than to a particularly genius approach by Reinhardt and company.
The characters who are portrayed as the brilliant great men, then, are so portrayed not because they are shown to be brilliant great men, but because that status is useful for other actors behind them - which is made explicit several times. Yang is initially very useful as a hero to Trunicht, while Reinhardt is the linchpin of the coalition of officers around him, threatening to fracture as soon as he suffers a breakdown for a couple of days. In his case it is Oberstein, arguably the real brains of the operation, who maintains him as figurehead.
History in the show is seen to be made through larger forces that determine the outcome of things, the characters can only be the vessel for larger forces, influencing what is already slated to happen at the margins. Which fits well with Yang - the historian - 's signature move, making the best of a bad situation.