Well, besides reach, there's also the speed of a weapon. And a knife is much, much faster than a spear, so while the spear has a greater reach, a knife has greater speed. Depending on the way you fight, one or the other might be better.
But besides that, your anthropologic approach has one major flaw: it doesn't take into account that most techniques don't have to be reinvented. It's not like mankind has to learn that you can attach stones to sticks, they have guns for Christ's sake. So which comes first is rather moot, since they can all be constructed. It's more about available resources and ease-of-use (and perhaps construction) than anything else.
And in that sense, bladed weapons might not be so uncommon, since smiths would be around to smithe tools. And there are plenty of metals around to re-use.
Although the axe and the knife would certainly be more common, if purely for the fact that they can be a very useful tool as well.
But besides that, your anthropologic approach has one major flaw: it doesn't take into account that most techniques don't have to be reinvented. It's not like mankind has to learn that you can attach stones to sticks, they have guns for Christ's sake. So which comes first is rather moot, since they can all be constructed. It's more about available resources and ease-of-use (and perhaps construction) than anything else.
And in that sense, bladed weapons might not be so uncommon, since smiths would be around to smithe tools. And there are plenty of metals around to re-use.
Although the axe and the knife would certainly be more common, if purely for the fact that they can be a very useful tool as well.