the topology should work out for such an old game , anyway to answer your other question , there is not much deformation happening at the upper half of his heads backside so don't worry about those triangles , you might want it to match the neck of the base JKA models I don't know how many sides it has to be right now though , just import your retopoed mesh into 3ds max import a base JA model and then scale and target weld as required also : try to get that head under 500 vertices otherwise it wont shade correctly ingame - sadly