Im kind of confused about the special units that require buildings to be built like royal guards, assassins, etc. Frankly, Royal guards come with 30 health, and naked. No equipment, no armor etc.  Is this the way its supposed to be? This is with most of the equipment already researched. 

Secondly, is there really no way to upgrade these 'naked' soldiers? I'd like to use Royal guards as the base, but if I have to buy each one new equipment from the store instead of being able to build the equipment during training, it'll make me go broke trying to equip both my heroes and my units.

So if there isnt a way, I'd like to suggest that the special units be 'naked' at base, and then you can upgrade them with your equipment you've unlocked as you see fit through the design menu.

Cheers.