Single plane air wing trick works extremely well for fighters, but for some reason the same method breaks CAS and they won't join battles if divided into ones. In fact, if you divide it at all it gets wonky and there will be a few planes that are, according to the effective number in the air zone, supposed to join but don't. But then I've also realized that I don't know the conditions of CAS ace generation, does anyone know what it is? It says in the wiki you get a role for ace promotion when killing a ship or a plane, but nothing related to ground combat is mentioned.