Remember when Oro told Kabuto to kill Sasuki; Sasuki is in the hospital back then. Then after telling to kill Sasuki there is a brief tense moment between Oro and Kabuto. It show that Kabuto and Oro don't meet eye to eye. I think Oro made a remark about him not knowing what Kabuto's true intention is.

Maybe int the later part of the series Kabuto's character may build up and turn to an interisting one.

PS: I don't really have the ep that im talikng about, maybe im wrong.