Someone who is more intune with game math please correct me if I am wrong but:

SCH shield is doubled when a crit happens. Doubling would equal 200% shield.
AST shields are 250% no matter what. 250>200 yes?

To through numbers out there: lets say I crit on SCH for 5500 heal. That gives the person I healed a 11k shield.
lets say I crit on AST for 5500 heal. That gives the person I healed a 13,750 shield.

So, now AST crit shields are also better than SCH shields who is supposed to be the "shielding" healer. Plus, AST shield is an instant cast.

Is my math wrong? If it isn't, than SE really needs to hire new people to do the number balancing. How can you give a healer who is supposed to be a substitute for either WHM or SCH all around better moves than the jobs they are supposed to be able to fill in for? IT DOESN'T MAKE SENSE!!!