I'am not sure it address the situation at all.
You buff SCH while he doesn't need it. Noct AST is still largely inferior to SCH.
You make some skills from AST and WHM incompatible, encouraging to not play them together (even if it's diurnal), so SCH will be desired more.
Lily ands traits from WHM shouldn't exist or should change completely.
You should create a situation where temporarly Shell and Protect are enhanced and become AOE, otherwise it would still be not interesting to bring him with the hope to occupy the shield healer spot.

Sealous Wind is nice, and allowing a compo AST (diurnal) /AST (nocturnal) with their set of cards is nice too.