ehh the argument could go both ways.
people bring up the 2008 kishi interview saying the Minato was the strongest dead character. (though it could be argued that he did not want to give away that the real madara was actually dead and people debate the exact authenticity of the interview itself )
people also bring up that the 1st defeated the madara while he had the kyuubi in possesion ( though it could be argued that minato could used a contract seal and teleport the kyuubi and Tobi isn't all that weak to begin with and the 1st would have trouble with Tobi due to teleport tech and abilities to become intangiable and we still don't know what madara's powers are exactly since we don't know who/what tobi is. and assumed to think that madara and tobi have the same ability since tobi claims to be madara)
for me I going to wait for two things before answer this: 1. Who the hell tobi is and 2. Edo Madara's fight
but if I had to make a prediction of the outcome of this fight it would be The 4th would come out victorious since in Naruto and newer generations always end up being stronger and surpassing their predecessors or senseis time and time again. Examples: Gaara beating his father, Orochimaru killing the sandaime, sandaime defeating 1st and 2nd (though kabuto stated edo forms only as good as their summoner), Pein killing jiraiya, itachi losing to sasuke( though he was sick). its happens to show growth and without character growth the story would go dull.