deathguard vs Raddagan vs Dark one

hi,
Someone could explain me what is the difference between this 3 sets , if I want to make an acid build which one would be better|?

https://www.grimtools.com/db/itemsets/122
or
https://www.grimtools.com/db/itemsets/138
or
https://www.grimtools.com/db/itemsets/134

Deathguard:
https://www.youtube.com/watch?v=0pReN1qxzsA
old vid, will be tweaked in FG

Radaggan:

http://www.grimdawn.com/forums/showthread.php?t=72799

Dark one:

I am sure many iterations are in the compendium

These are three very different play styles and skills that the sets suport. Just get what you like. You and a melee hybrid get deathguard, you want fun AoE+ almost never die caster get Radaggan, kinda same can be said about DArk one compared to Radaggan

Deathguard - Acid/Poison Reaper. https://www.youtube.com/watch?v=m8juxDobW6o&t=102s
Leechtank, lots of floating stuff around. Low OA. Low dmg against heavily resistant stuff, like MQ.

Forgot to say, full Radaggan is really vitality with secondary acid