There's been a consistent debate/request for stuns to be more viable in PvE, but in a way that's easy to understand for the player and not unbalanced, so here is my take on how stuns can be reworked for PvE only, they would remain banned in PvP/Advanced Combat. Since Beguile is linked to stuns, this would also change what enemies are resistant/immune to beguile as well.
Stuns would be based off the creature type of the creature. If a creature has multiple types, priority is given to the type which has the larger resistance to stuns. The three categories that all types fall into are Stunnable (No stun resistance at all, stunning these creatures gives them 1 stun block, with bosses getting 2 stun blocks), Stun-Resistant (20% stun resist, bosses have 50% stun resist. Stun-resistant creatures get 2 stun blocks when stunned) and Stun-Immune (100% stun resistance, cannot be circumvented)
Overall, if the creature is organic they can be stunned. If the creature is a larger, more resilient living creature, they are stun resistant. If a creature is an object or some other being, they are stun immune. A full list of every creature type is below for Stun-Resistant and Stun-Immune creatures. All final-world bosses/major world bosses (Such as The Scorpion) will be stun-immune regardless of what is written below: