My bad, I thought this thread was about Combat knives that could be used for Combat or general purposes in a combat roll.
You are correct that thin knives cut through some items better than others. For example: A scalpel cuts through tissue with fantastic ease, but no one would use it to cut down a sapling or tree branch with one.
As well as some types of edges are better suited than others for doing one task than others, like hollow ground, straight edges, chissel ground, serations, and wedge shaped to name a few. All of these have ther pro's and con's.
As I said, I must have misunderstood the nature of the thread. No disrespect intended.