i have a theory that obito disconnects madara from the mazou and kills him in order to hijack the moon eyes plans and having zetsu to himself thats why he was suprised when kabuto resuurected madara in his prime because they still have beef
true but they have a comman goalThey're acting pretty friendly towards each other if they got beef
thisit's simple because Madara was so infamous his very name inspires fear and the things Obito did people thought only Madara could do and as to why he was shocked about seeing Madara in the coffin is simple it's because Kabuto knew the the truth and thought he might expose him which would mess with his plans
This.They worked together. Obito took Madara's name because it produced fear and panic.