I disagree that it's a zero risk unit. It is so fragile if the enemy decides to fire back at it there's a good chances it will die. On top of that it needs to get close to actually do any dmg.
Id like the aoe far dmg buffed so it doesn't always need to be on top of its target to kill it.
I would rather have the calliope and the land mattress nerfed. It's basically hell for the axis whenever the allies bring those two units. A close range calliope barrage is basically guaranteed to wipe a squad.