I would say that the problem with your proposal here is that those "more details" you mention consist of a vast horde of information we do not know anything about that far outweighs what we do know. At best, we know that certain areas of the brain concentrate certain functionality, and we can map rough levels of interconnectedness and activity traversal. That is not nearly enough information to build a brain. The neural nets that exist may sometimes achieve "Human performance" at narrow tasks but it's a big leap to infer that those neural nets are actually functional models of subsystems in the brain, or that their isolated functionality can be plugged into a larger group of such neural nets and have something coherent emerge. Our actual brains are far more interconnected and overlapping than is obvious from reading the latest fMRI study.