Board Thread:Theories and Speculation/@comment-45444155-20200728155230/@comment-45444155-20200801134930

That's only if you see them as one.

In the data book, Kabuto had both Sage Transformation and Sage Mode. If there are characters in the manga that are Sages but not Sage Mode users, then I see no reason to think that Sage Transformation is not limited to the presence of only the Senjutsu chakra, and is analogous to the name Sage Mode.

Kabuto clearly considered Curse Mark Orochimaru to be defective, which acts exactly like Sage Transformation Jugo. If this is all Sage Mode, then there is no reason to consider Curse Mark a bottom.