The only thing that can solve that is experience
Still, we do pretty well when we're in-sync. We get some pretty nice team combos off. Some I remember...I threw your brother to you, you hit him back into my dancing blade while you charged a fsmash. Pretty nice :O
Also, when there is only one more person left. We just need to stick to you SH camping with me literally right behind you. If they manage to get past your projectiles, just roll behind me. I'm literally right there to swap them away before they get to you (yay disjointed hitbox :D).
Oh, also remember to SH when you're camping. You get more projectiles in quicker that way. And don't move forward, that makes it easier to get to you.