Purpose: To put a soft cap on the size and distribution of guilds.

Fluff: When not in direct contact with guild members the communication equipment and other connected systems are expensive to maintain.

Crunch: Charge the guild a small scalable fee for every member. Also for every two guild members that are not in diplomatic contact the guild is charged an additional maintenance fee to maintain the organizational communications.
How will this help: This will force guilds to use taxes or donations to keep the guild up and running if they spread themselves out too far and have members that are not in contact. If the fee scales larger as more memebers qualify for the fee then this could be an effective soft cap on guild memebership and advancement, but since it’s a soft cap it would make large organizations impossible just expensive.

Exploitable: While not an exploit guilds could get around this by splitting in to smaller connected groups. This would however make them less effective in war because of insta-deccing would not work.