Brutal Swing adds a whopping 4.167 potency baseline. If you honestly think that Brutal Swing is going to do *anything* appreciable to your total damage dealt, you're deluding yourself.
So you say that Spirits Within shouldn't be counted but Brutal Swing *should*? Silence is *less* useful than stun so DR means a *lot* less. There's only one boss that I know of where silence means *anything* (Dhorne Chimera) and, in that fight, you also need stuns.Spirits within is a Silence that builds DR. It is not part of any reasonably person's rotation on anything other then trash mobs, which should not be a realistic view on DPS.
Anyone that acts like WAR is more effective at AoE has no idea what they're talking about. Yes, Flash does no damage so any kind of AoE damage situation is naturally going to favor WAR; this would be true if Overpower was potency *5*. What you (and pretty much everyone else who always brings this up) is that Overpower has a *lot* going against it: it's *hugely* expensive (net loss of *80* TP per GCD, compared to the 10-20 of every other attack; Flash is, for all intents and purposes, completely and utterly free), unwieldy (*targeted* cone rather than PbAoE circle), has no secondary benefit like Flash's blind (minor issue, but still), and is smaller (120* cone w/ 8y radius = 67y^2 area; circle w/ 5y = 78y^2 area). The only advantages it brings are slightly better burst enmity generation (which comes at the cost of enmity generation down the line thanks to the massive cost) and the little bit of additional damage (less than any of your single target attack) that gets *easily* drowned out by the damage capability of any DPS you might be running with.That being said, PLD still does more more damage then a WAR on single target. WAR is much more effective against Multiple targets. I imagine if anything were to change with these two tanks, this would be the first thing.
On top of that, PLD also brings Circle of Scorn, which is flipping amazing: it's free, it's the same size as Flash, and actually deals an appreciable amount of damage (more than Overpower, in fact).
Overpower is not the Twelve's gift to AoE tanking. In fact, thanks to all of the stuff that it has going against it, it's a pretty fair balance with Flash and Circle of Scorn.