No problem. The more healers know about the differences between Tanks the better. As for War's, they do get a benefit from being in Defiance. Basically :
This ^
Defiance does not provide a passive defense the same way Shield Oath or Grit does to a Pld/Drk, but it does grant them access to their Infuriated oGCD's. Inner Beast, in particular, is a big one. They basically get +20% defense every 20s if they Tank while in Defiance.
That being said, there really is not much of a penalty for swapping to Deliverance once they gain that effect. Further, some of their defensive moves actually see better synergy when used in Deliverance. Blood Bath, for example, scales self-healing from the War's dmg output. Deliverance increases their Dps significantly, so the returns they see from Blood Bath go up when they use it in their Dps stance. If they pop Berserk with it they can essentially go without direct healing for the duration of the timer. So it's not uncommon to see a War cycle into Deliverance whenever Blood Bath and Berserk are up, to increase their self-healing. It's all about knowing when and where it is a good idea to switch stances.
As far as I know, this is still accurate, but I haven't looked into the War numbers since the patch. War's do, however, have a lower eHp while in their Tank stance than Pld's. Someone handed me my own ignorance on this one in the tank forums once before and ran the numbers to clear things up. In terms of flat eHp, War's come up short by roughly 5%. That being said, their Self-healing more than makes up that difference, so learning how to use those CD's efficiently is a good idea.