By doing so, she is once again getting the protection of a larger, more powerful group. It would be a smart, safe move for her to make. By moving over towards Kucha, Amber would run the risk of a backlash should Ogakor members decide to vote for her. Should a tie result, these backlash votes could come to haunt her. Even worse, should she make the final two, the Ogakor members of the jury she helped eliminate may not take too kindly with her actions and vote against her.
Strength is still an issue with the remaining tribe members.
Nick, Keith, and Colby still appear to have their physical strength and muscle tone. Ostensibly, these should be the ones targeted at the next tribal council. Strength becomes a weakness the farther along these players are allowed to stay in the game. Nick was the object of Ogakor's voting pattern until he won immunity due his strength. Now with Amber as the wild card, Keith and Colby should be aware that they too could fall under that microscope.