They aren't very useful even in the final stages, it's better to divide the Sorceresses, especially when breaking through defenses. On their own territory, only Golems are weaker than Minotaurs. Of course, taking into account their upgrades.
I've noticed this feature: in the game, there are several characters who are very slow, and fighting them turns into shooting at tough meat from a distance. Yes, as defensive units, Minotaurs are quite good (if you need to protect Sorceresses or Assassins from large creatures). On their own, as guards for a mine or passage, they are weak; it's not difficult to break through them, but their stats are strong – that's the paradox.
И пусть Эльрат осветит твой путь