ok..
1> not all uchihas gain the same ability through mangekyo...
2> only Tsukiyomi and amaterasu are not the requirement for Susano...two mangekyo sharingan are the requirements!
3> Sasuke and Itachi have similar(not same) abilities...as the same eye(Sasuke got Itachi's eyes) is being used.
4> for example, Shisui and Obito gained different abilities.
5> Madara just might not have amaterasu, he might have some other ability.
6> and about Tobirama, he also said he has seen many uchihas gain mangekyo...so, it is possible some other unknown uchiha had amaterasu.
again cuz it is impportant:: two Mangekyo sharingans(in an Uchiha, who has gained mangekyo himself) are required for Susano and not just two abilities(viz, Tsukiyomi and amaterasu).
PS: just an observation by me, but Kishi knows the best.