he was given credit for the 98 World Cup by the guy who actually won it - and he did coach a fair few of the players through at u18 and u20 level, so i can kinda see why he gets a nod there.
The Istanbul thing is interesting in that it often reflects a bit/feeds the narrative of those who it suits -i haven't expressed that the best but it's iike those who say Slot won the League with Klopp's team [Ignoring that Jurgen didn't for 4 years that preceded it] because they want to denigrate his achievements or big up someone else (Klopp - or GH at the expense of Rafa back in 2005)
To my mind - if you're in charge, you're in charge. It's YOUR team and YOU win it.
Fagan won the treble, not Fagan won it with Paisley's team
Kenny won the double, not with Fagan or Paisley's team
Rafa won in Istanbul, not with GH's team
and Slot won the League, not with Klopp's team
it must make life easier having players who have won titles previously but each season is long enough and presents enough of its own challenges to give the guy in charge the credit for title winning success.
and by the same token to stick the f***ing boot in when it goes wrong the following season, i guess.