Could you explain a little more deeply how you got from:
?From this perspective, the best type is all letters reversed (RRRR) or all letters the same (SSSS). The former gives more opportunities to cover each other's weaknesses, and the latter provides the best chance to understand the person's motivations fully.
(Personally I agree with the first comment better. The latter comment is a theoretical reality that doesn't seem to play out in real life very often. Basically, people who share all four letters often don't get together (too monotonous / same weaknesses in the relationship), and people who share no letters tend to just create far too much friction and have trouble connecting... unless they are both very stable to begin with and totally willing to deal with this lack of similarity.)
Usually people seem to do better if at least share either an S or N trait, even if they differ on the other three.