Oh its real discussion, I take it back i'm down for that.
Once you get percy crits never happen to you again so by the time enemys have critrates that are over single digits arthurs weaknesses are pretty negligible.
Elsie will natural max magic as will most dywers who care about it, ophelia effectively starts at 20/x with hilarious bases so she's bumping the cap, nyx is nyx, camelia has a full time job supporting, leo is honestly the only other relevant dust target and there's more than enough to go around. Edit: I guess avatar/kana could eat some???
Sorc is still honestly more useful for EP utility on odin/ophelia imo, they both have a lot of potential high move partners, bowbreaker is a fantastic skill, and while vengeance isn't the utterly broken POS it was in awakening it still has very real utility on the player phase for orkoing stronger enemies, keep in mind you have pretty free control of just how bulky you are on EP via debuffs/aura manipulation and nos is a flat one hit one heal no mods now so you can control the exact amount of hp you go into the player phase with which makes vengeance VERY consistent when stacked with the ham duo's absurd natural critrate and an arthur debuff.
Edit: To elaborate on why i'm not a huge fan of dark knight, you get leo who already does the job well enough, the army will likely have roughly a million birds/ponys by the time odin promotes, and you're extra move kinda gets ruined by the same things that ruin...the rest of the army at that point. Sorc honestly has more freedom of movement in that context. Also the main draw skill wise is seal magic, (oh boy lifetaker at x/15 to do the job of a 4k tome....once...on player phase) which is...a really easy re class if you need someone other than leo with that utility.
Basically it just offers more even after the nerf from lolgodofVV to a real class.