Board Thread:Naruto Discussions/@comment-24847491-20140921145042/@comment-1512913-20140922113012

I once (or twice) brought up a topic if Jugo should be added as Sage Mode user, I believe so. Merge and balance of natural energy with spiritual and physical energies results in Senjutsu chakra. Having Senjutsu chakra flow thorough your body results in an empowerment of it called Sage Mode. Sage Transformation is just that, save with body alteration ability as a bonus.

Those who opposed this did so with: "Sage Mode is more than just having Senjutsu chakra in body" even tho there's no evidence for their claims, quite contrary, that's what was observed.