Dunno if people would like to verify my statement but I've found the axe is a lot less effective vs. hoppers so it might be better just to run away from them. For the other zeds, it's just a matter of getting used to the real length of the axe (I remember someone saying its range is more akin to something like a 2H sword) and try to make the zeds approach in such a way that they can't easily circle to your right. That, and have lots of room to backpeddle incase you miss your swing or they glitch out a bit.