Well I understand why it’s not the same mecanism.
In fact, they are not minion, but for manifest armor, shield and weapon. They are decoy, and so need to get their own hp bar, so they are technicaly consider as minion. Exaclty like illusion from the mage teleport.
Forge guard has no passive for minion and that’s normal. Only some to augment hp of decoy.
For the damage, they have node to make then scale damage from the model equipment, that great it’s really the ability to manifest from the forge guard and no minion.
So you can’t compare with minion of others classes.
In diablo 3 you have the same with illusion from the sorcerer that create decoy taht mimic your skill at 10% damage. It’s the same.
The “minion” of the forge guard are temporary and not companion like beast master. It’s cool and normal that is not the same mecanism.
My only concern is how to scale damage from fire shield