answer to most to these is C4. deidara has more than enough time to make one and madara has little or no counter. with full intel he obviously will know about genjutsu or susano. 5 hours prep means he will cover the battlefield in mines and bombs. imagine having to walk through a forest covered in C3 clay.
Deidara lost to a MS-less uchiha he is absolute 0 compared to any EMS user...
deidara was a child whod never even fought a sharingan before. you cant seriously think deidara was at his best then. he spent every waking moment training to face itachi again and kill him.
and he doesnt NEED to be comparable to madara, just able to kill him.
madara still wrecks... TBB's bombs can travel btw
wheres he aiming? deidara with 5 hours prep would have scattered clones all over the battlefield, and C2 mines.
the instant the fight starts, C2 mines will start hitting him