Well, in that case, don't you already know the answer? Sure, one can multitask very easily with a hatchet, or even a big axe. No problem. It's got a sharp edge on it, so you can cut with it. But even if one can multitask with a hatchet to do small knife tasks, the hatchet still is, to put it bluntly, crap for small knife tasks. But me, I'd much rather bring something that does the job better, which is to say a small fixed blade along with the hatchet. Man has survived so far because he can improvise tools. Even if you haven't got the hatchet, or indeed anything in the way of tools, there's still a lot you can do with just your bare hands, including making some primitive tools if you really need them.