Caught this happening today. My buddy was like "what do you do when your allies are attacking you"? I said "I don't know what you should do but I'm gonna laugh and take pictures! It wouldn't have been so messed up except I noticed it was the guild leader and current overlord leading the raid!
A****les like them are everywhere around the globe why a game would be an exception?
Anyway until IGG introduce a normal diplomacy system as it was suggested in many thread before and make Alliances,NAP-s,WAR-s more effective like color based and you cannot hit who you are allied or NAP-ed with,until then this will be something you have to get used to it or until your guild represents a real threat so they think twice to attack.
There's so many good things they could add to the game but 100$ heroes and skins are the top priority because devs are dying from starvation probably and need lots of money as soon as they can and not the gameplay which only enhances the experience and the fun and diversity of the game ofc...