I don't think Lesbos can be considered an island (nor can Euboea) in terms of the RTW engine though. It's part of Asia Minor as far as the game can tell, since it has no idea about straits. The AI can easily move the troops across, it just is looking more to the west where its other holdings are. If it is isolated it will look to Pergamon, but the only real islands are Corsica, Sardinia, Crete, and Rhodes - plus the British Isles. The bad thing here as far as Maks go is that one of their possessions is isolated from the rest of theirs, and the AI doesn't like that part. I think KH and Maks equally get stacks "stranded" away from the rest of their cities by having them on Lesbos and Rhodes, but that is just the engine.