tl;dr I concur, Adriatic League is legit
7 year old article, lazy googling, ymmv:
https://www.espn.com/nba/story/_/id/18470135/fran-fraschilla-rankings-world-top-12-basketball-leagues-nba
Ranks the Adriatic League #8 in international pro leagues. You can throw out #1 -Euroleague, since it is...