I think the whole notion that the guy must be of help because he's genetically engineered is stupid. He might be more intelligent, but he did sleep for 300 years. If you brought Da Vinci into this time, he wouldn't be able to build a new aircraft carrier or aircrafts for the US Navy within a year.
This is sci fi, a genetic engineered human being can acheive whatever the writers want.
The fact that Khan is more than an ordinary human being is enough without going into all the boring details on how.