I do believe that xenoarg is in the right here.
In accurate circumstances, breaks should in no case happen, because you can't easily replace a shaft on the battlefield. That means the wood needs to be partly sheathed, made of denser wood and cut from the right grain.
And being a reeactor myself (having also been invited to shoots of 1066 
) I can say from experience that most wooden items are crafted so they are lighter and break more easily, to be considered 'safe'.
It seems to me that when it comes to Medieval reenactment and fighting practice, there's a difference between the general attitude and the ways of doing this in the Western and the Eastern Europe.
Again, there are different reenactor types. Some of them participate in gatherings or festivals to show how cool they are with their historically accurate arms and armor, to get together with their reenactor friends and have fun. Of course, they would treat shafts of their spears/halberds/poleaxes well. After all, they don't have any plans to break it, do they?
However, there is a different kind of reenactors too. I can hardly call them "reenactors", since most of them don't pay much attention to the actual reenactment of life of the Medieval-whoever-they-are. They are more like sportsmen who like to spar with cold steel in hand (again, I'm talking about Eastern European full-contact sparring here). So, if you are fighting with your spear or a poleaxe a couple of times per week, its shaft
will be hit quite a few times (probably, much more than the real 100% authentic Medieval poleaxe shaft was designed to withstand
) and
will eventually break because of wear. This is its fate. So, why should this guy bother to treat the shaft with all kinds of stuff just to see it breaks in, say, a couple of months of extensive use? Well, he could, but on the other hand, I've seen this kind of sparring equipment for quite a few times and the shafts looked like they didn't undergo any special treatment.
The funny thing is that all of us are trying to prove the same point: it is very unlikely that the shafts of the Medieval polearms would break on the battlefield just like that.
