Hello, Robert!

Please note that all actions in the game are made only after the appropriate commands which are sent by a player. When you manually select troops to send, other troops cannot be included automatically since this action requires your command. Please always double check the list of selected troops before sending them to a target.

Also, the troops which are lost on Battlegrounds will be included in the future rewards. This is why they are lost not for nothing and you will get a benefit for your losses. 

Since the issue has not been classified as a bug, the topic will be closed.