Agreed. I really don't get their thinking behind of parties and squads.
Surely the smart thing to do would be to have the party limit unlimited or set to, say 32, and the squads as they are. Then ensure ALL party members can all join the same server, putting them into as many squads as necessary.
The only way to play with, say 6 people, is for the party of 4 to join a server, one leaves the party AND the squad but stays on the server, starts a new squad (which is broken too, since there's no option to CREATE a squad - it always sticks you in another squad with people and it's often full) and invites the other two players.
Even this doesn't work after the game ends. Both squads then end up on different servers next game.