The thinking on players over picks is that you have a better understanding over who a prospect is a year or two after they were drafted. For example, there was much more confidence that Lindgren and Hajek would really be NHLers in March of 2018 than there was in June of 2016. Because of that, their value was greater than the 37 or 49 picks in the 2018 draft.
Also, you can accelerate things by getting young players who are almost ready to play in the NHL, instead of picks that you have to wait 3-4 years on.
But you have a point about being able to leverage picks into players later as well.
I'm not totally convinced the Rangers would not have been better off with picks concerning player like Howden, Hajek, Lindgren, etc. Not that I dislike them, just seems like they are going to turn into secondary players, maybe.
Therefor I'm not sure that is all that different than taking picks instead then using those picks for a higher potential player who happens to become available, Fox for example.
Rangers are a preferred destination for players, if other teams have to move someone because they just do not want to be there anymore, the Rangers have a pretty good chance at being on their list of want to go there. If so it may come down to if the Rangers have the picks as currency at that point or not.
To use Jost as an example, I'd rather have the picks and hope that some higher potential player shakes loose, whether that player be an on the cusp of the NHL prospect (Fox), a RFA who is doing the I'm not signing long term thing (Trouba), or even a good vet who is just looking to get out from where he is at.
I see it as remaining more flexible instead of just taking the best of whats available at the deadline, which when it comes to high potential near or already in the NHL players, it is pretty rare that they move.