I don't see how a team can win without making changes. Players blow hot and cold. The manager who can spot a Loaiza, Willis, or Podsednik first has a big advantage.
Of course if a manager is desperately chasing the hot player he's apt to unload better talent than he is getting.
With pitching, a good team can be bested in the pitching category by someone who swaps for the next day's starters. He may lose ERA & WHIP, but has a good shot at scoring more Ws & Ks.
Last year I was chasing a team with 5 Red Sox hitters. Finally, I added David Ortiz for those weeks I played him H2H and neutralized him. Also, the Red Sox cooled off late in the season, that helped too.
This year I'm in a 22-man roster league which will make adding & dropping more pricey.
3andOut: Whenever I feel blue, I start breathing again.