Exogamy yield stronger Offsprings?

Do Exogamic relationships yield stronger offspring? The reason being, the two parents being more gentically separate then if they were of the same ethnicity. For example, a Portuguese mates with a Amazonian; the offsping would be superior to a full blood Amazonian and a Full blood Portuguese becasue it would have genes from two very distinct groups. Modern Brazilians are the descendents of these 2 groups, and West Africans. Would they be the most superior people in the world?

On the opposite spectrum, high degree to endogamy has terrible effects on offspring health. The Amish for example have numerous abnormalities. Most of them are descendents of the same 500 or so first immigrants.