Title is supposed to be "Halo 5" button layout. I love that "zoom & shoot" was introduced, but it's frustrating that grenade is RB, melee is LS, and crouch is B. To mirror Halo 5, and pretty much every modern shooter, grenade should be LB, melee should be RB, and crouch should be LS.
I have this exact same problem switching between H5 and MCC. The default for H5 and the universal zoom and shoot for MCC are so close but frustratingly different. I would love to see a "Universal H5 zoom and shoot". Honestly though I think games need to start being more flexible and support mapping actions to buttons so people can create it how they want. I think this is common on PC games and I do not see a reason why this would not work for consoles.
I know you can remap buttons but there are two issues with that. First that only works with Microsoft controllers, my Razor does not allow remapping of standard buttons. Secondly, as someone already mentioned, it messes with on screen hints and general navigation of the menu system between rounds.