Ad hoc work groups, OER content groups or project nodes in WE should have the freedom to operate as they see appropriate. I don't see any need for ad-hoc groups to use the workgroup guidelines and these may perhaps be counter productive and work against the principles of self-organisation in open wiki communities. There may be ad hoc groups that are looking for tips on how to operate or work in a wiki environment and they would be free to use these guidelines for their own projects.
Similarly, a specific project (eg externally funded project) may have different process and membership requirements to those we are suggesting for community-wide work groups. These groups should be free to organise themselves as they may require.
I firmly believe (and have seen) Governing boards fail when they start interfering in operations. Ultimately -- work groups (of any type) work in the realm of operations. For this reason, Council should not exercise value judgements on a charter but rather ensure that open and transparent development has occured.
With regards to the criteria for a proposed workgroup to become an "official" workgroup, I've posted a few thoughts. Bar the exceptions of workgroups which may result in financial, legal or technical dependencies -- I don't see that Council needs to approve a charter. In my view, Councils role is to foster due process -- the Charter guidelines provide a benchmark for due process. If these have been adhered to -- then Council will need to approve the policy proposals developed by the "official workgroups." If not, they will need to be deferred back to the community.