The reason this approach won't work is that genes aren't linear factors that can added up together in that way. Even in something as simple as milk production, you need to do selection over multiple generations and evaluate each generation separately, building up small genetic changes over time.

If you could construct an actual model relating various genes to intelligence, in a way that took into account genetic interactions, then you could do what you propose in a single generation, but we are very very far from being able to construct such a model at present.

As it stands today, if you just carried out that naive approach you would end up with a non-viable embryo or, in the best-case scenario, a slightly-higher-than-average intelligence person. Not a super-genius.