I'm giving it to Pochettino because it seems he's actually transformed the style of his club and the condition of his players, and he's unearthed some rare talent. Players that were brought in by Baldini under AVB and flopped for ages are starting to find their feet as well—and the real dross is being cleared out.
I feel as if Koeman has inherited a solid setup from Pochettino, and has benefited from it albeit with a massive exodus last summer. Southampton are quite simply one of the best run clubs around—Spurs are not really at that level off the pitch, though they're a solid operation these days.
I suspect Koeman's the real deal, but his present situation could be compared to Laudrup's success after taking over from Rodgers at Swansea.
I would never give a job to Rodgers. He's clearly a gifted manager (the weirdo) but his man management gaffes and his eccentric personality are going to sink him at every club.