I just want to reiterate something to add to the original point: the less healing that a given encounter requires, the more it favors White Mage DPS. If we assume Savage content will be more difficult than relatively simple Extreme trials, we can expect WHM's relative DPS advantage to shrink as they are pushed to use more GCDs on healing.

Also, it's silly to compare top parses. Nobody is giggling and bringing a DNC to buff their AST to see if they can out-DPS the poor NIN, but I bet someone's doing that with WHM. The 75th percentile of parses is much more representative, and, surprise: the gaps are less egregious there than between the top parses. To wit, WHM-SCH is ~700 DPS at the average of the 75th percentile on Innocence, but the gap between top parses is ~1700; with WHM-AST it's 1500 and 2300, respectively. Losing a few Glares per minute to healing will close that gap even further. SCH is fine, aside from its usability issues.