If the Jets trade him this summer and its to the Habs, you are correct they either have a few good young players/prospects or nothing but trash. Again purely using your agenda of only to the Habs, we can assume none of those top prospects/young players would be included in a return. The only player IMO that has any value on that team outside of those young players is Dvorak and after this year he will have two years left on his contract vs PLD one year of team control. So Dvorak+ a decent but not great prospect (B level prospect, like Farrell, Roy, Beck, Kidney). People will rage, but Dvorak is a good 3C & great at FO's and those prospects are ok, not super exciting but ok, Chevy might also push for a mid range pick also. Small market teams operate at a disadvantage retaining players often.
Trouba returned a 1st rd and Pionk, at that time Pionk was not well thought of or liked by the Rangers. IMO Dvorak (2 years control) plus mid range (3rd - 4th rd pick) pick & one of those prospects I listed above is about similar value. Positive to it is let the Habs pay PLD 8.5-9.5 million per year after next season, frees up our cap. Of course the Habs could wait 1.5 years and then sign him as a UFA, but thats a big risk, bc we all seen players get lured by big money offered by other teams in the past.
That being said I don't buy into the idea Habs are the highest offer if PLD was traded this summer without some serious offers from other teams in need of a center.