Now, correct me if I'm wrong, but shouldn't sins be stacking Acc/Agil/DC, with their only sources of AC being buffs/armour/helmet/stone?
In theory yes. In practice no.
Sins need to stack just DC For most pve, sometimes ACC.
The issue with agil replacing AC is that mobs ACC is higher than an achievable AGIL high enough to avoid enough attacks.
We already pointed these issues out early on in the server and lightbody buff was doubled per level.
I believe this was delivered aling the lines of "with this new agil you can now dodge 1/3 attacks from mobs in stonetomb...
The game has of course moved on from there, AC gets higher with armour, level bonus' And gems/runes, AGIL doesnt increase any further aside from the odd gem drop(dont see many evasion ones)
New items are coming but its difficult to balance AGIL for pve and pvp..
So on topic- the class is flawed as the only sensible option is low level DC bracers instead of near enough pointles AGIL ones but at level 40 you cant wear them.