Every edition has had base guidelines for how much it would cost to hire a commoner, expert, lvl 1 mercenary, lvl 5 merc, etc. And the DMG has always had a few guidelines for people to expand upon.
But thats just it, they are guidelines! Why does everything have to be spelled out and spooned to us nowadays? 3rd edition quantified everything, and by doing so, some of the "magic" was lost from the game. Look how long it takes to run a simple combat in 3rd edition, and 4th doesnt look much better. The DM's job is to ad lib, to keep the game flowing, to work with his PC's to provide the best experience out there. And yes, sometimes you end up restricting a players choice, but if youdo they should understand why. Followers, cohorts, and even familiars are NPC's. They are not a second character for a player to have and run. If you run your games that way, thats fine too. personally I like to reserve the right for Joe the Cohort to say "no" once in a while. THey are supposed to be your freinds and allies, not your own personal expendable slave you gained just because you took a feat.
I agree with Aloïsius. Break out of the box a bit, use your imagination. ALL the rules, every single teeny itsy bitsy one is simply a guideline. Use what you want, discard the rest. Its your game after all.