Re: OCC Thread
You do get bonuses on defense for multiple opponents, it's not a 100% clear, but the book reads "when two or more attackers gang up against a single target , their actions gain a +1 bonus for each attacker, to a maxiumum of +4 (more than four attackers just get in each other's way). It says "actions" as opposed to "attacks".
Mike and Daniel will be able to join in after this first round, their perception and notice plus any hearing bonuses are enough to get one success level before the dice is rolled, which is enough to hear the fight going on.