4v4 has some pretty iffy technical problems though, with the game quite often slowing down to half speed with a full match, also with the only 4v4 map being a CP one, that plus slomo means that you can easily end up with 40min matches ++++ when both sides are good and one side isn't just holding it all the way to 650.
Also just jamming two random teams together doesn't mean they can fly together effectively.
3v3 might be doable, but even the biggest clans might have problems filling 3 ships, let alone the smaller ones who have to shuffle crews every week anyway.
Not saying it should or could not be done, just that there are practical concerns.