Ashura's chakra(Hashirama's cells) + Indra's Chakra + Natural Energy (Jugo's cells) = Tomoe Rinnegan.
The Juubi is nature so it makes sense that one would need senjutsu of some sort to get a Rinnegan with tomoe. Also the same area Kabuto injected Hashirama's cells is the same area Jugo gave Sasuke part of his flesh.
OT: I highly doubt Kishi would hype up the power of having two Rinnegan's if Sasuke wasn't going to get it later in at some point. Perhaps he already has it in the other eye but sees no need to use it.
So if Madara has Ashura Chakra(Hashirama's cells) + Indra Chakra + Natural energy(Hashirama's sage mode) would he have nine tomoe rinnegans?