My opinion is that social combat and physical combat shouldn't occur at the same time. However, the rationale behind my position differs from the rationale ways and means presents for why some prefer to separate social and physical combat.
According to some peoples interpretation of social stress is entirely external too a person as it represents how other people view them. According to these people attempts to use intimidation to scare some one would not be social combat and attempts to persuade someone to back down from a fight would not be social combat (perhaps the only uses social combat has ever been put to in my campaign).
I don't believe that social stress is entirely external to a person, it represents not only how others view a person but how a person feels about how others view him. For example, a social consequence could be "Tarnished Reputation," which is entirely external, or it could be "Shamed," which conveys a change in the subject's thoughts or behavior based on how others view him. Sometimes social consequences are like "mental lite," damage to a character's self-esteem or ego that isn't quite potent enough to be mental stress. Social combat is a lot more nebulous than physical combat, in terms of duration, content and consequences, which is part of why I think the two should be kept separate.
Whether a situation becomes a social combat is, for me, entirely dependent on whether a physical fight is taking place. In fact, a character could perform the exact same action, such as trying to intimidate someone, and my answer would be different depending on the context. Is social interaction all that's going on? Social combat. Is it taking place in the context of a physical fight? Count it as a maneuver that can be tagged or invoked for effect.
If this is the cannon interpretation then social combat seems meaningless outside of a people in organisations or politics game and a large number of creatures should get automatic social immunity by simply having completely alien societal norms. If this it the correct interpretation of social combat it seems that for a large number of games mental combat would be far more common than social combat. Because of those comments I am considering abandoning the social and mental stress tracks and replacing them with a composure and fatigue stress track in my game.
Am I misinterpreting social combat or is it meant to be only used in a political game?
To me, social combat can encompass a staggering variety of interpersonal situations. A staredown at the bar with people throwing intimidating glances at each other, an election race between two politicians, a tense business negotiation, a high-society gala with mingling and backstabbing, a frat boy sweet-talking a sorority girl. Honestly, mental combat seems like it has two purposes: as an add-on for physical combat (governed by powers which explicitly allow for its use in physical combat), and for those rare situations where things get really psychologically intense for a character. In contrast, social combat, with its own initiative system and collection of relevant skills, seems equipped to handle all of those situations where physical violence isn't happening.
It's not that I think social and physical combat can't be mixed, I just think the system is more elegant and more balanced if they aren't. Opening up the social stress track during physical combat devalues physical combat skills, and especially abilities like Toughness, if a social character can just ignore those extra stress boxes and target the vulnerable social stress track. On the flip side, keeping the social arena separate gives socially focused characters a chance to shine. Furthermore, adding in another stress track just gets plain messy and confusing. Treating Intimidation attempts (for example) as a maneuver in combat makes for a simple and elegant solution that keeps the focus on the physical combat while still allowing for the social skill to have a potentially huge effect on the combat via an invoke-for-effect.
Anyways, that's what works for my group, YMMV.