Sadly what you're suggesting speaks to a much bigger scale than anything we've seen confirmed for Sea of Thieves. Even the incentive to play as a 4 man group other than fun with friends isn't there a lot of times. Personally I think the glaring lack of options on this front speaks volumes to how little Rare understands what gamers want from an online multiplayer game. You could literally form bigger groups in arena shooters on the OG Xbox.
The talk around PVP balance in this thread is amusing. Oh no! Those guys teamed up to earn a sparkly coat faster than everyone else?! How will I ever enjoy the game? Given how centered around cosmetics the progression shown off has been I can't possibly understand why so many of you think you need to enforce how others play the game. Unless we get some major unforeseen changes, and actual penalties/consequence for losing, the risk/reward factor is already next to zero. This game is as casual as they get.
Besides my regular crew has been press-ganging random crews to team up on the server for months. Bigger groups just means we won't have to tell our 5th who showed up 5 minutes late to start server hopping or [mod removed] for the next few hours. If we want to talk performance issues with bigger crews that's one thing, but if you want to talk balance as Rare works to add a sniper to the game... Lol okay.
I love how things like the low encounter rate and even crossplay balance get so casually dismissed because Sea of Thieves isn't a PVP game, but then in the next discussion the competitive integrity of the game is all that matters when people want better group (or even PVE) options. I'd be willing to bet the applause around here would be pretty unanimous if Rare decided to add expanded group (matchmaking in general) options in the beta.
Going to be an interesting 3 months as this community continues to grow to say the least.