I prefer when teams transition on the fly while trying to remain competitive. I think it's better short and long term. The idea that you have to suck to be good is a fallacy. Two or three exceptions, but the best teams remain consistent. They might have a bad year or two but try to make the playoffs every year.
The isle, Florida, Carolina, Toronto, Buffalo, Columbus, Edmonton, Colorado, Atlanta/Winnipeg, Phoenix/Arizona, have all spent years in the basement rebuilding. A few have had a decent run or two and eventually the law of averages will have a couple of them succeed but - it's not a good way to build a team.
Boston is in the same group as San Jose, Philadelphia, New York, St. Louis, Detroit, New Jersey, Anaheim, LA. Year after year they try to ice the best team they can and aren't built on years of suckage.
It'll be tough for Sweeney to identify which ones, but he's going to have to move some prospects to shore up this team. Chiarelli came under heat when he moved kids like kalus, karsums and lashoff and the 16th pick for vets but it worked out especially holding onto Marchand, krejci, lucic, rask.
Not easy but better than building from a couple high picks that may impact and create a winning core.