I find the Imperial Heavy axe length change curious. It will either be a major buff to one of the best infantry classes in the game, or it will inadvertently nerf the unit due to causing them to actually hilt hit like some of the other axes. Right now the Legionary is THE best heavy infantry in closed spaces and amazing at hugging other units due to the speed and short length of their axes.
As you wrote, the risk is making it the same as the sturgian heavy axe that is so long that hardly does damage because the swings mostly don't hit with the blade..
Sturgian axe is on 93 or 96 length (with the axe perk) so the empire's in theory still won't be as long and could actually be decent. To be seen really.
But, what i want to say with this post is, maybe decreasing the length of the sturgian varyag axes could be the buff that sturgia desperately needs.
Right now, upper hits seem to be the ones who reliably get most damage in for varyag units while side swings are a big maybe.