Let me try asking you this then:
Can we have Sonic - the Hedgehog in Fallout 3? I mean one could make a Sonic Fallouty kind of game, blending Sonic, Tails and Big Cat in with say Deathclaws, supermutants, raiders, and ghouls. I mean, both exist in sort of a Fantay world, right?
Or as Brother None once asked on the Bethsoft forum? Can we have a pink (I think it was pink?) elephant in Fallout 3 or maybe unicorns or the Mako or Gorion in Fallout 3?? (notwithstanding the legal problems).
The point is this:
A game world exist in its own right. Within this game world there exists certaain rules that apply to this world. This is what is known as verisimilitude. This means that the rules of the world internally may not be broken when you add something to thr world. As such you really cannot have say unicorns or pink elephants running around in Fallout 3 nor can you suddenly have magick as a big part of the world.
Luckily, Bethesda seems to have understood that magic isn't a big part of the world out world, instead they just think that over the top Quentin Tarantino ironic & satiric violence is. I fear that they Bethsoft, especially maybe Todd Howard can't seem to come over the impact that perk for 'bloody mess' has done to him, when playing the first two Fallout games.
I think the question many Fallout fans, including me, now have: is this satirical 'bloody mess' combat where you see blood & gore & parts flying everywhere when you shoot someone with a critical hit really a part of Fallout? Most Fallout fans, including me, will say *NO*, I feel.
And why is this?
Quite simply, because we understand that Fallout is not just about running around in an open world shooting people while watching their heads or legs explode. While this could be fun, of course, it certainly does not feel like it would be at home in the Fallout universe (at all). Of course, there's a twist to this, since the 'bloody mess' perk is at home in the Fallout universe, but as I understand it, whenever you enter into the VATS combat mode, and choose which body part you want to shoot at, the game first pauses, then unpauses, and you then watch a cinematic video in slow motion. And when the bullet hit, you will see the full impact of the hit. That's suound too me much more like the type of bullet time type combat found in say Max Payne 2 than the original 'bloody mess perk' in the Fallout series.
Of course, there is one than one way to make the game world believable within its own rights. I haven't seen that many objections to Bethsoft's adding a few Radio Stations in the game nor have I seen many objections to Bethsoft's way of handling character creation and possibly a few other things as well.
The thing is still, though: It has to be fit into the pre-existing game world - to make sense in the game's world. Or in the book's or the movie's world: This means that in the Harry Potter universe, Ron and Hermione just suddenly can't be friends with Harry anymore nor can Dumbledore turn out to be a big bully. In the Harry Potter universe, there are thestrals, flying cars and magic. If these things weren't there, it would not be the Harry Potter universe. Likewise, it would not be the Fallout universe if there wasn't the brotherhood of steel, preserving their own way of life.
The brotherhood of steel is not the raiders of the wasteland that beth apparently wants them to be. It does not fit with the overall (established) gameworld...