Both Bielsa and Sampaoli have managed in club football successfully in south america.
Now european club football is a different kettle of fish but that's point 5 dealt with.
Bielsa favours working his team to death with high energy attacking football. He tends to have huge success at first but then his team gets knackered, falls out with him and he leaves. He is in no way a man for the long term and he's not imo what we need at this club.
Sampaoli won a continental title with a chilean club by beating much richer mexican/brazlilian clubs which proves he can fight against a financial gap, which has to be a key consideration at this club.
He then did well with chile, knocking spain out of the world cup and winning them the copa america for the first time. He also likes fast agressive hard working football with emphsais on coutner attack and pressing.
Counting against him is he left the chilean national team job because of huge corruption, fraud, bribery and tax dodging which he was 100% a part of so he is not a trustworthy person. And he has never managed in england nor even speaks english.