I grew up in a church tradition that had a lot of committees. The Personnel Committee hired and fired staff; the Curriculum Committee picked out what Sunday School classes would study; the Facility Committee picked out the color of the carpet, (assuming they could ever agree themselves on what color the carpet should be). 

The benefit of committees is that you make decisions with an abundance of counselors, which is wise (Proverbs 24:6).

The problem with governance by independent committees is that you tend to have groups of people making decisions without a perspective of the whole. You invite a silo mentality that inevitably breeds conflict and division because committee members don't have access to the big picture. 

In the best case scenario with independent committees, there is a Committee that oversees committees. However, even then it is next to impossible to get anything done. The oversight committee has to inform all the committees about the decisions of the other committees. Each individual committee has to report to the oversight committee concerning their activities. This opens up an almost infinite number of extra lines of communication, all of which provides the potential for misinformation. 

It also ensures that the majority of your people will be governing ministry, but will be so leveraged in meetings that they'll never get around to doing it. That also breeds division and conflict because each committee will begin to resent those who aren't members of their committee because they aren't doing the kind of ministry the committee directed. The truth is, they'd love to but they are tied up in committee meetings of their own. 

My advice is to simplify your structure as much as possible. Streamline your committees and eliminate as many lines of communication as possible. Otherwise, you'll find yourself hamstrung with meetings, laden with conflict, and looking for a way to blow the thing up and start over.