Well The BG and BT are the only ones with their BIG nares sticking out (
@Shezbug ) Which is why they are always listed first when we read about pulmonary hypersensitivity syndrome.
You can always spot a BG hybrid when you look at nare placement.
Scarlets are very candy apple red while GW are quite crimson. No facial lines, they have thin hairs on their face which is why his cheeks don't focus well.
Beak is completely different. GW have a very wide bottom jaw where the scarlet is tight and tiny. A GW will grab and bruise your whole arm severely without sometimes breaking the skin. A scarlet will grab only your skin and rip a massive hole in your arm.