Eddington was Canadian, though. We have no law to fit his crime.

He betrayed his uniform!

The Bajorans were a native people occupied by a foreign and extremely abusive power. That’s pretty cut and dry.
The Maquis were upset that their settlements were traded in a wartime treaty without their input. In a perfect world they would get to stay on those planets, but they weren’t native and the issue is muddier.
But most importantly, Eddington just didn’t fit into his uniform quite as well as the Major.