Clan "practice"

I think it would be a neat idea to let clan members attack each other to practice attacks and strategies. My clan has talked about it and would be fine with not receiving any sort of reward from the attack such as no trophies or loot returned I say this because people would take advantage and use it to "farm trophies or resources". The attacks would not interfere with ones shield and would be strictly for practice or fun. It is always nice to know who you stand up to in clan rankings. It would help coordinate clan wars better too.