Would you believe I’ve actually thought about this before?
My conclusion: it depends on TOS or AOS versions. In TOS, I’m not certain, but if the safety of the ship is at all concerned the better money is on Scotty. This is the man who picked a fight with a bar full of Klingons over an insult, and he’s got a bit of a physical edge in weight and height as well. Kirk’s fancy break-dancin’ fighting moves can’t save him now.
AOS, on the other hand? Sorry, AOS Scotty, but Simon Pegg is twiggy compared to James Doohan. It’ll be a fight to see, but Kirk is gonna lay you out flat.
So has anyone ever thought about how bad Scotty’s hearing must be? I mean the man spends all day in the engine room without any earplugs. Bones must constantly be yelling at him to take better care of his ears, damnit!
My dad was a merchant marine engineer in the ‘70’s before he switched to teaching and his hearing is messed up because of it. And trust me I’ve been in ship’s engine rooms, those places are noisy af.