However, Linus’s kernel was more elaborate than GNU Hurd, so it was incorporated.
Quite the opposite.
GNU Hurd was a microkernel, using lots of cutting edge research, and necessitating a lot of additional complexity in userspace. This complexity also made it very difficult to get good performance.
Linux, on the other hand, was just a bog standard Unix monolithic kernel. Once they got a libc working on it, most existing Unix userspace, including the GNU userspace, was easy to port.