Drop groups of troops at once.

Hello,
I couldn't find anything related to this in the rejected ideas and had a quick search through the existing threads as well. So if I missed it I'm sorry.
I had the idea of maybe an extra building like a portal that allows you to store a number of your own troops that you can drop in one group when attacking. As this building is upgraded you can store more troops in it. At the moment you can only deploy a steady stream of troops one by one.
I think it would help with strategy during attacks particularly during clan wars when you get stuck with that higher level player that you need to attack.
I hope you find my idea interesting.