We often consider Austria one of the great powers, but the Hapsburgs would have been a shadow of themselves by the 1700s if they didn't have Hungary, Bohemia and Croatia. Arguably Austria wasn't a great power outright. But then neither was Hungary. But the Hapsburgs (Habsburgs? The British spell it with a B?) were certainly very influential and it's hard to say it wasn't a great power like France of Russia, even if it did suffer some losses. So if Hungary and Croatia, and Bohemia are traditionall not considered great powers, but then arguably Austria isn't by itself, maybe we should say the 4 of them made a great power together?
But if we go by that standard, OTL Hungary met the condition already, even though it had its fall from grace.
Also Hungary doesn't strictly need to assimilate Croats or Poles. Medieval and early mdoern Bohemia was a mix of Mostly Czech speaking people but there were people who had German, Croatian, or Hungarian as their first language. As long the idea of the nation-state doesn't become popular among the peasant masses, whoever is on top doesn't need to waste resources trying to force assimilation. Rebellions in the Middle Ages and the early modern era were religious issues, some noble who claimed a throne, or the nobles and the crown together squeezing too much out of the peasants (like trying to raise taxes in the middle of a famine https://en.wikipedia.org/wiki/German_Peasants'_War), not some notion that the locals are a different people who need their own state. So if nationalism is a yawn in TTL or even if it is a yawn in Hungary, there is no need for them to view minorities as a successionist time bomb because they're all people who are just trying their best to make a living. Everyone just wants prosperity and to live the good life. the mercantile class wants to continue the ques to make more money and the farmers just want full bellies
But if we go by that standard, OTL Hungary met the condition already, even though it had its fall from grace.
Also Hungary doesn't strictly need to assimilate Croats or Poles. Medieval and early mdoern Bohemia was a mix of Mostly Czech speaking people but there were people who had German, Croatian, or Hungarian as their first language. As long the idea of the nation-state doesn't become popular among the peasant masses, whoever is on top doesn't need to waste resources trying to force assimilation. Rebellions in the Middle Ages and the early modern era were religious issues, some noble who claimed a throne, or the nobles and the crown together squeezing too much out of the peasants (like trying to raise taxes in the middle of a famine https://en.wikipedia.org/wiki/German_Peasants'_War), not some notion that the locals are a different people who need their own state. So if nationalism is a yawn in TTL or even if it is a yawn in Hungary, there is no need for them to view minorities as a successionist time bomb because they're all people who are just trying their best to make a living. Everyone just wants prosperity and to live the good life. the mercantile class wants to continue the ques to make more money and the farmers just want full bellies