Every single bow has incorrect arrow paths, with arena out I've played a lot of each and I've noticed that the crosshair isn't the issue, it's the bows themselves.
For example on barb throwing axe doesn't deviate from its path indicator no matter where you are to your opponent distance or height wise.
Longbow either shoots under or over the guide line depending on where in the arc it is and relative position between you and the target, so there is a small Goldilocks one where it's correct but it's around the very edge of the distance multiplier distance.
Shortbow and recurve bow both randomly shoot somewhere near the crosshair but not on it, and where it shoots feels random depending on what room you are in. I usually test shoot at a random thing in every room I enter just to see what kind of extra lead I need to use there.
I haven't tested the crossbows or the handbows much but I'm pretty sure the Crossy also has the short/recurve bow issue