For me it has to be Klopp. Constant turnover with his squad, but still made them competitive every season. Ancelotti is a great manager, but not what I imagine FSG are looking for. He tends to take over teams full of world class players ex. Milan, Chelsea, Madrid, PSG. On the other hand, I'd say look at Milan to see what he's capable of. He groomed a young Kaka and Pirlo. On the other hand Klopp signed several players for modest transfer fees and transformed them ex. Hummels, Lewandowski and promoted players like Sahin and Gotze. I'd say the man has a good eye for talent.