Agreed, you've got Hamilton there to step right in and start at shooting guard and with everyone else in your lineup you could afford to give up Kobe (as odd a thing as that is to say) and still have a very impressive starting five.
If he's playing well and you're winning, I'd suffer the lower chemistry. Otherwise just look around for a player you'd like of equal value, make the change and hope for the best. Perfect chemistry is a pretty lofty goal and for the most part unnecessary, so you might hit a wall there.
playing well? who? bosh? in defense yes, but not really in offense, i overhaul my roster. right now i have A. jefferson(81) C. bosh (90) C. anthony(91) B. gordon(83) calderon(77) R. hamilton(82) R. Stucky(81) gomes(75) maxiell(72) speights(71)
i only tried this roster (didnt save the game yet)