Challenge friend's clan

Add something that enable leader or co-leader to send a duel request to a friendly clan from the friends list.So they can have a war to see whose clan are stronger . The challenger will set the number of member that join the war and as the requirment they both need the same number of the specific town hall level that join the war. Example, if the challenger pick 10 town hall lvl7 and 10 town hall lvl8, the challenged clan need to pick the same amount or they can just let the game autopick and balance the strong between the two clan.

I like the idea but there should be no rewards or gaining of loot since it would be abused.