Tienety's suggestion about this unit:
This guy look ridiculous with one-handed axe without shield. They can get second axe to left hand. Also, They can gets two handed axes with Piercing axes update.
Maybe this two handed axe:
So, Guardians will look more dangerous.
Also, this is very similar to current Erebors guardians weapon upgrade mechanism, when Erebor Guardians get siege hammers, that weapon is two handed.