Both of these classes can't be taken until level 8, and with the shifting of some of the other PrCs to work better in EfU's low lever setting, possibly a new oveeride version would encourage taking them?
I'd say, drop the BAB requirements by one. Seven is a lot more reachable than 8, and I think part of the reason Pale Master's been so popular is you can get into it early, without having to powerquest to reach your goal.
Ideas:
For the AA, reduce the power of the fireball arrow to 5d6 and give them Seeker Arrow at Level three.
For the Dwarven Defender, give them damage immunity 5% at level one, 10% at level 3.
Um dwarven defenders are pretty beefy Egon, they don't need a buff.
Just get rid of the requirements and have the prestige classes given to worthy players playing their builds, and characters, and I think you'll find that both of those classes are excellently balanced.
Having played AA, they are a powerful class...if you hit it, you won't be disappointed!
I assume because of the BAB needed for the class though, one gets.. one level of AA at most? or are there many level 12s on the server? How does it work in EFU:A?
I don't think it's too bad as it is, if you get to lvl 8 you have +1 arrows, ALL THE TIME, and then if you get to lvl 10 you have +2 arrows, ALL THE TIME. It shouldn't be too hard to get to level 8 since you're an archer not a frontliner
Especially non-rogue, high-hp archers.