It comes down to which players they trade for.
NJ screwed up, they traded for Meier (1st and 2nd) and gave him a big contract, signed Hamilton, Palat, etc.
Suddenly a rebuilding team with two #1s (luck) and some other young players turned old overnight.
They should have continued the rebuild for a couple more years, built up critical mass, then struck.
Flyers should be looking for a player like Reinhart or Tkachuk, 26 or so, who can contribute at a high level into his 30s. That's worth a couple late 1st rd picks and a prospect, but that's the move you make AFTER you're already a PO team and your 1st rd picks are in the 20s every year.
The stupidest move is to give a 29 year old FA, coming off his peak seasons, a 7 year big money deal.
If you want patches, sign 30+ year old veterans to 2-3 year deals that won't block all the prospects you drafted.
One reason I was OK with extending TK was I'd rather extend my own player, who I know is a good fit, than gamble on a mercenary. TK will be 28 when his deal starts, but $8.75M will be the same the first season, and far less by the end, in terms of a % of the cap, as the 5 year deal they gave JVR at 30 or the 7 year deal they gave Hayes at 27.
You need a few core players in a rebuild, Couts, TK and Sanheim are those players. Michkov will get his big 8 year deal in two seasons. So they don't need to overpay big money FAs. Even Couts deal, an overpay due to his injuries, will be reasonable for a top 6 LW in two years (the Cap will be $95M next season and over $100M in two years).