Well since you said no Edo's I'm assuming that means that Madara doesn't have Hashi's cells+Rinnegan combination because if he does then either he's an Edo (which you said is against the rules) or he's an old man that can't even move outside his cave since that's when he awakened his Rinnegan when he was alive. Also Itachi is at the mercy of his aids so...
Hashi (for Madara), Naruto (for Sasuke), Minato (for Obito), and Nagato (for Itachi)
And don't say I can't use Nagato please. I know you are going to probably complain about this since non-edo Nagato had to rely on his 6 paths of pain technique and you'll probably say that makes things uneven but it's a legitimate technique that any Rinnegan user can use (and Obito technically has a Rinnegan and can use 6paths too)
The way I see it, if everyone is fighting seriously, Hashi either defeats old man Madara with Rinnegan low diff or young Madara mid diff (whichever Madara you decide to use). BM Naruto beats Sasuke mid diff, Minato beats Obito with his speed high-diff, and Nagato just stalls Itachi with his 6 paths until Hashi, Minato, and Naruto arrive to finish the job
**Edit** Better yet, I could also let Nagato deal with Obito and then have Minato just run around and drain Itachi's chakra. Itachi would have to keep his Susanoo active just to keep from being one-shotted with FTG. All Minato has to do is avoid getting hit (which he's way too fast) and Itachi will probably end up killing himself