This isn't a Linux kernel clone. The whole argument is that producing a "bug-by-bug compatible" Linux kernel clone should be much easier to pull off than a "research kernel" where you may get lost in exploring design dead ends.
Or, the original claim: How small a team, and how quickly?
Sure, the Linux development process was inefficient. There were a lot of false directions and dead ends and things that were OK ideas but were superseded by better ideas. If you know the destination, you can drive straight there without all the wandering around.
But, fine, how inefficient was the development process? 90% wandering around? It probably wasn't 99% wandering around. So you're going to need something like 10% of the man-hours that went into Linux.
You say Rust is more productive? How much more? Maybe a factor of two? OK, you need 5% of the man-hours that went into Linux, over the last 20+ years.
That's still not a small team and quickly, no matter how you slice it.
