The problem with mage shields is that they only absorb X amount on a hit. Our BS can smack someone for close to 2300dmg with his buffs running, so the 500dmg a mage would not take is not much, which granted is 20 percent roughly. However, in group situations the shield is spread out against the whole group, not just the mage (aoc gold). And every person in the group does not get a 2k shield; it is the same 2k for everyone.
The other point brought up about the range, it is true casters has it better when it comes to keeping targets in range, compared to the sin and most melees. But a guard with a pole arm has a huge advantage over the sin as well. We have seen a guard circle a sin and not get hit because of the pole's extreme range. We provide age of conan gold for you here.
And lastly, we did point out that many melee classes in AOC have dots or bleeds that do not have reduced splash damage, the hox for example has burn to death, the bs has bleeds, sins have bleeds. We believe conqs have some type of bleed. A while these combos are not ideal, the same is true for casters who see a heavy reduction from their primary target unless them use channeled or long casting aes.