IMC, leadership is not required. If you want a cohort or an underling, just let your PC acquire one through roleplay.
For me it is absolutely clear that a player plays only his PC, everything and everyone else is controlled by the DM. That means that the PC can give an order, but the player does not play the cohort - the DM does.
So far one PC imc has a student of her martial arts school (trained from level 1 to level or 6 now) and hired a former enemy as a personal guard. They may qualify as cohorts, but then that PC has also hired another PC as a bodyguard (dirt-cheap, poor barbarian has not much money-sense), and is the owner of the genie bottle another PC is bound to (It was that, or getting summoned by who-knows-what-mages for all sort of odd jobs). Full share of loot for all PCs is unheard here, but then the players do understand that their PCs will be provided for with gear anyway.
I try to "blur" the line between PCs and NPCs as far as the social pecking order is concerned - i.e. the cohort of a PC may very well be able to order another PC around. All is voluntary, of course - I do not force any player into such a social hierarchy. If they want their PC can be indipendent and work on his or her own powerbase instead of being part of another PC's.
