good luck next year signing 12 players to get to 23 with likely less than 30 million to spend and 2 of those guys being matthews and marner.

I would want nothing to do with Dumba. Another offensive guy..

Any trade involving Nylander that doesn't result in the capable defensive 1RD that TOR's been hunting is a failure. Your usage straight up admits that you didn't get it.
Nylander was also slightly better than Marner at 5v5 this year, Marner's boxcar stats (and trade value) were inflated by having power-play god James van Riemsdyk on his PP unit. Trading Marner probably makes more sense.
TOR is an awful fit for JT: JT's prime will end well before his contract does, and that contract will probably waste a year or two of Marner/Matthews' primes.

The failure is the

You're right bu this type of scenario is even worse as the Leafs would have to carry over all their PB till next year which would reduce their spending even more next year.
Trouba at 7m seems like an overpayment, but there is seems to be some fascination that ALL RHDs.