There's a difference between skewing and skewering. There's no jab; it's simply difficult if not impossible to calculate the contribution of shields if they are being overwritten and you have a constant stream of shields that aren't being consumed. And that 200 is at the bottom of their range. At the top, they can go 600+. A SCH doing 200 DPS is still pulling a good bit more HPS than you possibly can.

Forgot to adjust for overheal on the Nocturnal AST vs WHM comparison. WHM is 50~% stronger. Your numbers are also far too small. More realistic would be 1500 vs 2600, but this is before the numbers are adjusted for overheal. After overheal it'd be like 1300 vs 2000.