Max probably just has his number. I say that only based on the fact that Aldo tooled Frankie worse than their first fight and that was only a year and a half ago.
Max is a great fighter. Look at his run. Two wins over the GOAT fw- and they were violent stoppages. Wins over credible people like Lamas, Cub, Heathen (who the fook?), Pettis, etc. You don't go on a run like that without being an awesome fighter.
Plus I think Aldo has always had conditioning issue but that guys with good cardio like Frankie and Lamas and KZ could not really exploit it because Aldo was their superior standing and in the grappling and they were sort of lulled into playing a conservative game that Aldo could do for the duration because of his abilities. Coasting is the wrong word but it's almost as though Aldo had a game that could utilize his strengths while preventing other fighters from getting traction going.
Max fights with both a disciplined approach but also does not hold back from taking some crazy risks every now and then and pushing the pace. Those types of moments force Aldo to fight at a more wild, frenetic pace than he should be given his cardio. Max knows he can fight for five rounds easy so it's no sweat off his back to lure Aldo into a brawl, force him to throw heavy and then pour it on when he starts to fatigue.
You could see in the latter half of the third how well those dividends paid as Max looked ultra fresh and Aldo had nothing in the tank.