Why the difference in duration?

[RaquelleAvarosa]

I think Raquelle is wondering about the refresh duration, not about the enmity part.

Raquelle, I have only unlocked astrologian and never played that job at all, but could it be that astrologian has a higher MP consumption compared to Whitemage? If so it would explain the longer Refresh time.

I play both jobs a lot. IMO, WHM consumes more MP than AST.