The idea
Seirul·lo's socio-affective superiority is what happens when players who identify with and understand each other connect. The Messi–Alba diagonal is the famous example — Alba starts his run before Messi even looks up, because he already knows the pass is coming. That is not magic. It is years of the same academy, the same principles, the same reps, turning into an almost telepathic understanding that lets them act in hundredths of a second.
What it tells me about how I build a team
It tells me relationships are not soft stuff off to the side — they are a performance advantage, and I can train them. Keep partnerships together long enough to develop a language. Deliberately rehearse the combinations that create goals, together, rather than leaving them to chance. And it connects to something I already believe: if everyone in the group learns the same principles, even the bottom of the roster becomes easier to play with, because they speak the same football. Understanding is developed, not assigned.