If they're fighting all at once, as the thread starter has clarified, are we counting total damage or kill shots? Because someone might steal all the kills while everyone else does the damage.
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Anyway, presuming it's current Cable, I'd give the edge to Spidey. Peak humans (DD) have been shown not to be able to take down Sentinels easily (or at all) but we know Pete can from the Onslaught saga.
Maybe Batman, if it's older versions of Sentinels that are vulnerable to EMPs. Otherwise, Brcue couldn't do muchtoward racking up a large body count.