If you want to completely miss the point, then sure, you can ignore how it had the rest of the covenant, marines, and all of the usual weapons and vehicles.

Halo 4 starts out with Master Chief and Cortana, alone on a sheared-in-half spaceship, above some forgotten Forerunner planet. No covenant, no covie weapons, no covie vehicles, no marines. Given the condition of the Forward Unto Dawn, there's not much MC can do to salvage any of the remaining weapons and vehicles on board, nor is there any way for him to restock once he gets to the planet's surface.

So it's pretty much just Master Chief, Cortana, and Forerunner artifacts, with no obvious story reasons to include any of the standard Halo enemies, allies, weapons or vehicles (other than maybe sentinels and flood infection forms). Potentially an entirely different sandbox. Now do I actually expect 343i to make a game called Halo 4 and not include grunts or ghosts or warthogs or plasma pistols? Not really.