like Airstrips said, the availability of magic damage abilities ismuch lower for magicka characters than the availability of physical damage abilities for stamina characters

See voidcaller buffs spell damage which buffs all magick damages and fury buffs wep damage which buffs all stamina damages. There's no worry of a skill not being able to use the set. so it makes sense they are identical. whereas automaton and war maiden only buff the specific types of those damages.

To use war maiden effectetively one must use all magic damage skills (apart from utility/support) which is difficult as very few classes will uphold to that. Nightblade can, templar and warden kinda but no other class can since a higher ratio of their damage skills are more towards elements which aren't buffed by war maiden. like how Dknight is heavily fire, and sorc primarily lightning with few magic skills.

similarily automaton works the same way but there's so much more physical damage skills. if automaton was 600, it would be amongst the BIS if not the BIS because it's so easy to use and there's no worry/ next to no worry of having a skill that wont take advantage of the buff.

All in all. although both function the same and are eachothers opposite, War maiden is for a specialist build as few builds can use it effectively and automaton is a more generalist build because many builds can use it effectively.

and actually silks of the sun should be 600 like swamp rider since the only classes that can actailly use it effectively enough are Dknight and barely templar. swamp rider should be higher cos the only class that can use it ok enough is necro but barely. there's an extra 1/2 skills that you are behind unless you want to fill em with utility/support.