Clan Troop Reservoir

The general idea is to have one enormous clan castle where each member can donate troops and withdraw troops.

During an attack, if a certain setting in your clan castle is on, the clan castle will withdraw random troops from the reservoir. The cost of the request is automatically deducted from your elixer balance.

This should only happen when your clan castle is completely empty. Also, there should be an additional bonus for elders in that there will be a higher chance that the elder will get troops of higher quality.