There sure do seem to be some wild imaginations in this thread.
Yes, years later, after hitting waivers and UFA multiple times, Marchment has unexpectedly moved up from 25-year old AHL grinder to complimentary NHL depth. No GM in the league saw that coming, or they would have grabbed him on waivers. Sometimes players break out down the road in different situations. It's nothing to lose sleep over. That's hockey, and it happens to every team. What's most important is that GMs are making the correct decisions based on the available information at the time.
Tavares is an excellent player, he brings a lot of positive impact and fills an important role, and after not even just adding him but replacing departing players with him, we improved in most skater measures he'd impact and are now one of the best teams in the league. You can't just arbitrarily claim that the team lost playoff rounds, so X player you choose on the team is useless.