Game and Game2 hand the merged mod data to Strings.load right after the mod merge, so a translation mod's strings registry is what Strings() answers from. Game3:_loadMods did not: on a FireRed boot Strings() kept the catalog the launcher preloaded, which is every enabled mod's lang/strings.lua whatever game it targets, with no defined precedence, and never a registration made from mod code. Call Strings.load(self.data) after the merge, as the other two games do.
thibautbus