there are a few answers to this, but one of them (that i like to apply to rafa) is who and what has he improved as individuals since being in charge vs. who has got worse under him say
if you view poch from that perspective he's done a great job, unless you think kane was just going to become the best striker around on his own and so on...as much as i think the praise sissoko is getting these days is a load of bollocks he's turned the signing around from being an absolute joke to, well, a footballer
objectively i actually "worry" about spurs for the point leffe raises, they've been gambling for ages with recruitment getting steadily worse and poch has been improving players papering over the cracks this whole time