It would actually be both more and less. I can Chain an RoS Greater Magic Weapon to get a +23 to attack and damage to each one, and also they have a large crit range and I can Reach+Chain Dolorous Blow so it becomes 17-20/x3 and auto-confirms.
However, even with the +23 to hit and a Divine Power, I'm still only at +50 or so to hit, which may not do so well. At least 5% of them will hit, and will confirm. So, I'm at 5% success which gives ~5 hits, each of which does (8192d6 + 23) x3 = 172170 average damage. Not bad... and if +50 gets past AC then I'm much higher.