Medron,
There are many reasons that the League won Atamara. Good diplomacy, Strong military leadership (Enri Kinsey is one of the top 5 generals of all BM history in my opinion), and strong loyalty. But, a huge component of that is multiple characters per player. Even with a good military and good diplomacy, the CE bloc would have lost the war to end all Atamaran wars when the entire island teamed up against them, if it weren't for double characters.
Also, it is completely disingenuous to act like the League has only just won Atamara. He League won Atamara the day Falasan fell. Everything since then has been inevitable assuming the CE bloc continued to push the toxic agenda of forcing everyone else out. You've won once you control more than 50-60% of the island. After that, it should have been changed. Not wait another 5 years to make sure everyone leaves Atamara.
