The outcome really hinges on the specific conflict involving the space marine. Yet, purely from a biological and statistical standpoint, I’d bet on the space marine. They're far stronger, have acid glands, a healing factor, and can often resist bullets even without armor.

Space marines definitely have some serious advantages in a conflict. Their strength and resilience make them a formidable force to reckon with. It would be interesting to see how this specific conflict plays out considering all these factors.