I think you can (in many cases) go the route of hiring a green OC or DC.
After all, there are more and more teams being added to GLB every season and everyone wants an "experienced OC or DC". Just not going to happen. Especially with the time commitment involved. I used to OC for 4 different teams and now with all the improvements to the depth chart and AI, there's just not time for it. I've cut it back to two teams and that is incredibly time consuming as well.
There are some things that you can look for in a rookie coordinator that might clue you in to how good they'll be. May require a little "interviewing", but that should be expected.
1. (and most importantly), make sure the person knows football. I know this seems obvious, but you'd be surprised at how many people don't have a clue or are just too young. make them prove it somehow. but try not to come off as a jerk.
2. see if they have any programming experience, even a little bit with something simple will ensure they aren't confused by the AI. can also ask about what they major in, or majored in (if in or out of college). anything like math, statistics, comp sci, engineering, etc should be viewed as huge pluses.
3. see how quickly they respond to all your PMs. if they respond quickly every time, or at least everyday at around the same time it'll let you know they're at least on the site often enough to put in the time required. also ask them about how much time they have to spend on GLB a day.
4. see how many other teams they GM for and what their role is with each of those teams. if they're scouts, recruiters, or other non coordinator positions, that can be good since they have some GM experience. any "honorary GM" jobs don't mean anything. also, if they are GMs of many teams, it probably means they don't have time to be your coordinator and cover responsibilities of other teams at the same time.
5. ask how long they've been playing GLB, and then check their ID# to see if they're a liar.
there are plenty of other ways to be confident about hiring a rookie OC or DC, there are probably many very good coordinators that don't get a shot because they don't have experience. just do your homework and ask plenty of questions and you'll be fine. getting someone with no experience and good "credentials" that can spend a lot of GLB time working on your teams AI is better than a very experienced OC or DC that doesn't spend much time working for your team.