Give that there was a whole ship full of Vulcans (Intrepid), even when TOS was the only series, Spock being the first was doubtful.vulcans in starfleet before spock because as well know spocl was the first vulcan in starfleet it says so right there.
Well the Kelvin was from a separate universe, so a Kelvin exact design would be strange. But a ship larger in size than the TOS Enterprise is possible.There's nothing in TOS to say that there's no Kelvin-type ship
The writers guide said something to the effect that the Enterprise's ship class was the largest, but nothing on screen ever backed that up.unless Kirk ever said the Enterprise is their biggest ship