Not a clue, but probably shows his eye for talent wasn’t all bad. Think he had a positive influence on a few of our better signings too.
GLC/Tanguy were & are talented footballers who lots of scouts probably rated & their issues have been more mental or injury related than anything to do with talent.
I don't think it's fair really to just look at Ndombele and Lo Celso then say 'Poch couldn't spot talent.' He overhauled our squad when he came in and built a pretty bloody good one when he first came in, so unless he had absolutely no input on the successes, you have to say that he can pick a player, just that he doesn't have a 100% success rate.
There's not a single manager out there that does though.
GLC is one that I feel has a question mark over him though. I do feel that there is the talent there but, as you say, there were circumstances that led to him being a flop for us when he first got here. He had no injury history before us, was playing for Poch when he was fixated on that midfield diamond that failed badly, was in and out of the side through injury's etc, and would likely have been questioning being there with the manager churn.
Personally, I'd be happy to see if he begins to enjoy AP Football and starts to realise his own potential. He's first choice for his position with Argentina for a reason, and it's nothing to do with favouritism. Get him playing and we have a better midfielder than Liverpool will have with McAllister.
Ndombele I don't blame Poch for, as the vast majority of us felt he would be the perfect Dembele replacement.
If AP can get him playing anywhere near his potential, then that would vindicate the choice.
I'm not convinced he will, but I've seen stranger things happen.