Conduits vs Duct Banks

My situation:

I have direct buried conduits (i.e. those conduits that have been directly buried in the ground and are not in duct bank).

I have conduits located inside tunnels and basements.

I have duct banks which contain an array of conduits (buried).


Would you suggest creating 3 separate feature classes? or would you create one Feature Class with Direct Bury Conduits, Conduits inside Tunnels, Conduits in Basements, and Conduits in Duct Banks as subtypes?

Any ideas are welcome.