Manage messages perm shouldn't be allowed to delete messages from users with a higher role

i.e. Role A is above Role B
If both Role A and Role B have the perm to delete messages, Role B should be able to delete messages from any user except those users who have Role A, because Role A is higher than Role B

Mainly, it's dumb that an admin/owner can delegate a moderator of a channel with the delete messages perm, yet that moderator can still delete the admin/owner's messages