Based on what I've seen from popular open-source Python projects I've used in the past (Fabric, Haystack and basically anything else by daniel lindsley) having a single human gatekeeper is the express lane to hell. If you do that make sure you have at least a few core contribs who can approve commits.
There are an awful lot of maintainers for smaller individual pieces/subsytems of the kernel. Take a look at the MAINTAINERS file to see who is responsible for the smaller chunks:
I've never even looked at any linux source code, but I still know there's too much of it to believe Linus reviews and signs off on every single commit personally.
