Naruto and Sasuke obviously lose. Flash BD would be their strongest technique, and Half Kurama+8 other Bijuu would easily overpower that.
Madara wins since the Bijuu can't overpower his final BD barrage used at VoTE.
5 Bijuu=Flash BD. Half Kurama can use the same size BD thus Half Kurama+5 Bijuu would produce the same explosion that happened when BM Naruto clashed with the other Bijuu. Adding 4 other Bijuu would almost double it's power, but not quite. And double that is still not superior to what happened at VoTE, so their attacks would clash, and Madara's PS would protect him while being on it's last legs, while the other Bijuu die a terrible death.