If your solution to bring players over to Astrologian is to buff it; please, just don't.
All it will do is push WHM out again, pulling over players that want to play WHM and not even appease the main issue actual Astrologians have with the job.
Spend that energy actually making Astrologians happy, and people who want to play the job will play it because of intrinsic joy, not extrinsic efficiency; even if the numbers aren't quite on par with the others.