a simple suggestion, being able to add pouches to mounts. If the mount had armor, only small pouches. if the mount has a saddle up to medium. if the mount has no saddle, up to large pouches.
No one would be able to ride a mount with no saddle, so that would be ineffective. And I doubt spiders would be able to carry things in pouches, large though they may be.
Not a bad idea though.
What do you think?