Quote Originally Posted by Rhas View Post
Additional retainers can be purchased via Optional Services.

Players may purchase up to two additional retainers. The purchase of an additional retainer will apply to all characters on a single account. However, a single retainer cannot be shared between characters on a single service account.

If I read this correctly, doesn't this mean shared storage between multiple characters
You're reading it wrong. Bolded the relevant portion. It just means you don't have to buy a 3rd retainer on each individual character. Charcter 1's 3rd retainer is still separate from Character 2's 3rd retainer, just like their first 2 retainers are.