Slot and Trent are more than good enough for Slot by your definition, we aren't going to get this mythical perfect RW and RB with 10 days of transfer window to go but if both are good enough Real Madrid and PSG then they are good enough for Slot who has so far won accolades in Dutch league. Let's not turn Slot into some mythical Pep/Klopp beater yet, he has to earn that and he can earn it with two players who are super talented.
I have not even mentioned what I think of Slot - so I don't know where you equate him not thinking Salah/Trent being right for his system with him being a top top coach. I don't think that all, I was just implying that maybe the output produced by Salah/Trent in games is not enough for Slot. It all starts being honest with what we have witnessed from both these players over the last two seasons:
1) Trent - lack of willingness to defend, one of the players along with Mac10 who has been got passed by opposition the most, not knowing what he wants - midfield/RB ? - take your pick. I don't want our team to play 90mins of football, relying on a few moments of Trent hollywood balls.
2) Salah - yes the goals have been coming, but in terms of effectiveness over 90 mins per game, we have witnessed his pace being less, and also very limited number of times where he beats players in a duel. The later might be something that Slot expects more from a RW role.
So yeah - Slot might think for the points I have picked neither are right for the football he wants to play.