Sharing Relics

Because of the Loyalty/Honor Points, leaving the alliance is less desirable, but if you spend your HP on good items in the alliance store, leaving and returning has little impact. If someone in the alli needs relics for a second or third city, and other members have them, the "needy" member can drop from the alliance temporaily and send wagon attacks at a city of a member that has them.
 * It helps a lot to be close to the city with the relics (Radagast Gift can get you close enough usually)
 * Wagon attacks are enough to get relics
 * Repeat attacks as often as you can
 * Existing walls need to be taken out by troops first, then wagons are fine
 * Re-join the alliance.  A regent or VR has to accept you back.