Godskin duo was definitely an attempt to do O&S again. The arena even had similar pillars for you to use. Much like the crucible knight duo, their aggression was toned way down so it is very manageable, although fireball was harder to deal with than crucible knight gap closers since they can do it out of neutral state. They are also significantly easier to stance break so bursting one down is fairly simple. I think their moveset doesn't quite synergize but it does by enough. Funnily the fat one is the one that can be baited to be overly aggressive this time. I think my only complaint about the fight is that you are not rewarded for downing both before a resummon. That would have been a cool little reward.
I assume this has to be the last duo. I can't think of another enemy type to make duos out of. Overall I think for relevant ones double gargoyle was the hardest, and the rest had sufficient AI aggression adjustment to be fair. Those that did not had some kind player side advantage going on (such as pre-emptive strike on the double beastmen in the cave in Caelid, or usage of Torrent against the double pumpkinhead). On top of ash summons for those that need it and/or various ways to output obscene amounts of damage, I think duo bosses in this game were pretty interesting overall.
Time for you to read the 15 page topic ERA has for the dislike of this boss lol