I'm far from being a LAKERS fan, but it was just a few years ago, when Kupchak hit a (yet another) seemingly home-run when he snagged both Nash & Dwight ....... the kind of move which likely makes you a contender.
Everything affects everything - injuries and some other things happened and the LAKERS didn't win a championship. So, break it up again and rebuild from there.
Ainge's CELTICS meanwhile has been on a longer rebuilding plan - stock up on picks and value signings until they pay out or until that next big free agent signing.
Bottomline, cant really compare the two since they didn't start and deal with the same set of circumstances. Over-paying Kobe was probably imminent given his standing as a player and his past achievements.