The reason Sampaoli is on most people's radar is because of the football he makes his teams play. The style, pressure, movement that consists of some of Barca's fundamentals. If success was the only factor then you could list a dozen of more coaches, but is that the only, and the most deciding factor when appointing a coach? In that case, why didn't we appoint Jose Mourinho in 2008?
It's not a premature discussion. In that case every transfer speculation or questions or discussions about signing a player is premature. Why even bother having any discussions before July? The title of the poll literally says 'IF Lucho decides to leave'. You don't need to discuss a dozen of candidates in one single thread or poll. This is specifically about one coach.