Yes, Pochettino got sacked at Espanyol. He then went on to be successful at Southampton & Spurs in a top division. Ole has only failure stories in top divisions, no successes. That's the difference here.
Well managed club? Very good players?
- pleaseeeee! We were behind Everton when Poch took over. Most of our team were mercenaries. We had some talent in the team (What? Ole didn't?) but it was very raw and untested. He had barely any money to change that, whereas Ole just broke the record to bring in a central defender, and had 50m to spend on a right back. Added to that he has talents like Rashford, Pogba, De Gea, Martial etc to work with. Let's not pretend the situations were hugely different - both teams had some talent but were struggling to make it count, and were on the periphery of the top six. The main difference is Ole had money to invest.
If you only view 'success' through the narrow prism of silverware, then yeah he's had no success. But that's obviously stupid because bringing a club in the top 4, getting them to the CL final etc, these are achievements for clubs and more important to a club than the league cup, fa cup etc. There's a reason Pochettino got hailed by people, he took a club on a low budget, nurtured the talent there, gave us a system and made us one of the best teams in the league for years. You don't have to think he's a great or up there with the very best managers (I can understand that) but to say he's not had any success just because he hasn't won a trophy is Paul Merson level surface analysis. And yes, he is clearly different to the guys you named, and 99% of our fanbase would find it laughable that you compare him to someone like Jol.
Maybe he is overrated, but he's levels above someone like Ole, a manager who has failed at his only two opportunities in the big leagues. And he shouldn't even be compared with him at all.