Multiple clans in wars/ Co-Op wars

For example, I have my clan as well as an allied clan. I could send the allied clan a war request, and they both battle another 2 clans, where in both friend clans, chat is open, as well as donation.

Or also, since when we begin the game, goblins are the primary enemy, 2 clans can cooperate and fight a goblin clan, chat and donation between both clans is open. The difference between both my ideas is that here, the battle is 3 days,and everybody has 4 attacks, since goblin bases are stronger than our bases.

What do you guys think?