EV's will definitely be the better choice on a champ spawn, aggroing more targets and spreading more damage. And if all of your enemies are provo'd air is a very good, and often neglected choice. All of the magery summons also don't need a secondary skill to be fully effective.
Not that RC would be an effective tank on its own on a solo run against a peerless, but against something like Navery the RC holds up a lot better than the magery summons. Having a choice depending on your situation would be the beauty of having both Mage and Mystic.
I would also argue that since you're not getting hit, and all nearby enemies are properly provoked, being dismounted isn't as much of a disadvantage. At least until you are juggling provokes over a wider range than you really should be, which I do a LOT. But the OP seems experienced in the bardic arts, so my RC suggestion doesn't really apply for spawning or situations with lots of provokeables; just those times when everything else is dead, and you're stuck with the 1 badass.
You raise a good point about WoD dealing direct damage, which interestingly is the flip-side of the point I also wanted to raise. Against a high resist target you will probably deal more damage with WoD. If you can debuff the resists into the negative with discord (which our friend, the OP, will soon fall in love with... Once he gets over hating training, lol), chain lightning --or with discord+necro, meteors--would be pretty nasty.