No prob! Maybe there can be both options? Rewatching the video, I would also add it seems there is a slight downtime before you can click and drag an object, after you have clicked and dragged a previous one. I think 0 downtime would be better, I'm not sure if there is a way for my suggestion to be translated to mobile, and honestly you probably should keep the drag and dropping for mobile, it seems most succesful mobile games (i.e. candy crush) use dragging and dropping.