Look closer. The hatch is only half the size of it's outer collar... and you might want to have a look in those windows too - they're about the size of the bridge one. See inside? Well in that case you're screwed, since the Enterprise was designed to look cool - in 1964. Every single ship in Star Trek's 46 year history has been designed with visuals first and foremost in mind. Form with function as it relates to Star Trek? Shouldn't you be trying to convince me the Enterprise is the shape of a rocket, or perhaps spherical? What sense does the Enterprise's shape make in the first place? What sense was putting the bridge on the very top level, completely vulnerable? And how do you define "making sense" with regard to a fictitious spaceship? It's all make-believe. The old Enterprise can be 289m while this one can be several times bigger with no trouble at all. Remember that insanely huge mushroom-shaped spacedock in the classic movies? If Starfleet can build them, ships like the USS Enterprise and the USS Vengeance are nothing in comparison. There is NO in-universe reason why they can't be the sizes ILM claim, and no real-life reason, either. I'll say again, you're arguing what you want the ship to be and not what it actually is in the film.