The help menu references the concept of items being 'Soulbound' so they're locked once equipped and can't be given to another. I think it's really good they dropped this odd, MMORPG type mechanic. But, that said by dropping it they left a big hole. I agree with mdonais that without a cost (time, mana, other) it's open to abuse and encourages annoying levels of micromanagement. (re-equipping armies before each battle)

Master of magic had a mana cost when items were taken from the item treasury. (To represent translocating them with magic). I think a delay when a runner is sent proportional to % map distance or a mana cost that is proportional to item power would work. That way instead of paying twice (time & mana) it's a choice between cheap or fast.

i.e. when you equip an item from the treasury outside of your territory have it ask:

Send item - 2 turns
With a tooltip that reads:
"Send the item for free, carried by a rider. Option unavailable in enemy territory (owned land)"

Translocate item - 5 mana
With a tooltip that reads:
"Use magic to translocate inanimate objects. Cost proportional to enchantment strength. An item with a soul cannot be translocated safely."