There's, like, zero chance you could get anything resembling what the current BP team would make if you went through a studio team. We have a lot of stupid design habits due to playing FS2 for years (we make everything WAY HARDER than retail FS2!) We also have a lot of stupid storytelling habits, in that we are wiling to predicate major story beats on tiny trivial facts about the FS2 canon.
The BP you guys get is...really the product of a pretty unique process, which I've seen at very small indie teams but never really in a big studio. (Back when dev teams were smaller I'm sure this was a lot more common). I've never really been on another HLP team that works the same way either, with the exception of JAD/Wings of Dawn (in that they're basically the same awesome dev team).
Most other teams I've been on (Bungie included) were basically 'everybody go make a mission/asset/whatever, come back when it's done,' and good luck if you want to have a lengthy conversation about the storyline or lore without somebody saying 'go ask so and so, I don't really know that stuff.' Obviously there were checkins and design briefs and feedback, but it was all — quite bureaucratic, y'know? It wasn't a constant organic bath. Testing also tends to happen in a separate bloc from design: the mission/asset gets made and goes to test, then the designer gets a pile of feedback to fix.
BP development is ludicrously iterative and kind of relies on having a team that's soaked to the gills in BP lore. You make the beginnings of a model while chatting on IRC, you p3d it, everybody talks about its tactical niche and what kind of economic conditions it was built in, you do some more work on the model, people post concept art and ideas they love, people fight about what weapons it'll have.
You make the first three minutes of a mission, you SVN it, you say 'hey play this' on IRC. You get people back asking you how you justify this mechanic fictionally, or whether it's really fun to have that ship bathe you in flak, or whether this wing could really jump in that precisely. The mission gets played probably hundreds of times before it's even done: everybody's on IRC hitting it back and forth, you try to smoothe out the rough spikes, make sure it's not self-playing, tweak all the AI behavior to fit the fiction, rework the mission loadout to fit the theater logistics, add some interesting new mechanics, cut the stupid cruft mechanics Battuta added, make sure the dialogue isn't too far up Battuta's ass, put in more Seraphims for Hades, etc. People will get in (friendly) fights over when a ship's beams should be ready to fire, or how a certain missile decoy should work fictionally. There's a lot of detail obsession. The most fun part is trying to find cool easter eggs to add, like a Kentauroi having a primary lockup, or a ship in mission 13 getting really mad if you killed her brother in mission 2.
Same even goes for weapon design. You'll have a bunch of people all co-editing a spreadsheet and trying out new variants via rapid SVN updates.
It's a super fun development cycle and when we're in fun crunch it goes 24-7 all around the world. But I just can't imagine the chemistry scaling up. We've been really, really lucky in that everyone we've added to the team has also been a great IRC player and a good fiction contributor.
BP works because the mission designers, the writers, the gameplay designers, and even the artists are all (mostly) the same people. That means you can integrate all the disciplines to tell a story. Bigger studios, man...it's almost impossible to keep everyone excited and on the same page about a complicated story.
I think two of BP's biggest flaws are an abundance of single-mission mechanics (Starcraft 2 style) and a story that can be hard as heck to follow if you're not a massive lorehead. Those probably would've been fixed if this was a larger production (although Assassin's Creed sure did get a ways with an incomprehensible story!)