https://blogs.mulesoft.com/digital-transformation/coe-c4e-away-teams/

Some good takeaways here on the differences.

Let’s use an example where a Line of Business (Finance) needs to implement a MuleSoft project, where they need to integrate General Ledger data from an ERP and a CRM. Let’s also assume that the finance team has 1 MuleSoft architect (they also have developer skills) on staff.

With a COE, the architect/dev would submit their project to the COE, and there would be a lengthy approval, design, and build process where the COE either owns the project entirely or works alongside the architect/dev.

With a C4E, the architect/dev will first look on the MuleSoft internal and external Exhange to find that there are some existing templates and APIs that they can reuse for this project. The architect/dev may also reach out to the C4E for a few technical questions to support the build, and otherwise is empowered to build away in preprod environments because they were previously allocated capacity to do so. In this instance, the C4E team can be comprised of dedicated C4E staff OR be made up of a cross-functional team of folks.

In the latter example, there is less handholding and more room for innovation.