First off, the greek nations are overpowered, including minors (Macedonia isn't *really* a minor), because there is so much greek culture and religion. Being able to invoke blessing of cupid every year with 90% success rate on top of all the conquering options gives you wayyyy more manpower than the culturally diverse Rome.
Yes, Macedonian is different culture from the other Greeks, but it's still a big step in the right direction. Especially with blessing of cupid and the ability to colonize on culture/religion right away (whereas roman colonies start off Etruscan or Osco Umbrian).
Secondly, the (other) screenshot shows 654, not 554. 654 is quite possible. I know as Rome I got locked into badboy wars around 530, and once the initial WE/manpower drain got under control, it was quite easy. The hard part was Seleucia. I suppose as Macedonia you could fight them early, before they control so much territory - the biggest block of all to WC is the simple fact that you can only take 3 provinces at a time from a Seleucia that can get to 50+ provinces. 51/3 = 17 = 85 years to conquer - and that's assuming there's no delays from sieges, etc. As Rome it's just too far away to mount a good war (the attrition from boats is murderous, and under new rules, you can't reinforce when you get there).
Well, that, and the fact that the game just gets outrageously tedious at that point. It was sort of fun to see "Mediterranean Control" go up when I conquered Carthage, but 5 years of replacing governors just to have another war with Seleucia... boring.