Haha.
Main issues I can think of, off the top of my head:
Are ducal capital extra recruitment slots? Or do they replace capital recruitment altogether?
What about duchies without cities or strongholds, can recruitment be implemented in other region types? Let's also not forget that strongholds don't actually offer banks unless they are a realm's capital.
What region is the capital? What if the duke doesn't have a lord? What if he's a rural lord?
Could this incite realms to create a million duchies? One noble One Duke?
Probably some others but duty calls and I gotta rush out.
