Most of the time I bring a 1h as a sidearm for my bow, just like most archers probably do. There is of course the possibility to bring a 2h at the cost of one quiver and a smaller bow but you almost never see polearms as sidearms. As a 3rd person only player, this is why:
Polearms on your back are perfectly aligned to stick right into your reticule and block your view. I like polearms a lot more than 2h weapons but I cant equip them without gimping my aim.
So, would it be possible to simply mirror the alignment for polearms on your back or just when you carry a bow ? If it would point to the upper left instead of the upper right ( like it is the case now ) I dont think it would interfere with your reticule that much.
Pro arguments would be of course more diversity on the battlefield.
And as a little extra for our anti-ranged lobbying folk:
With polearms being viable for ranged, they all would want to try it out, meaning they have to get lost of one quiver which is equal to less shit flying towards your 2h-wieldig plated ass.