I quite like that people can silently reinforce other players.
It adds nice level of complexity to settlements. Rather than the game play being simply - find someone who is smaller than you and bully them - it suddenly becomes far more complex.
But if it becomes common knowledge who is reinforcing who then all that extra level of gaming can be lost because:
- the defence is not as effective is people come to know that player XYZ is in a particular settlement
- people might not want to lay traps for people if the knowledge of who put up the trap can be traced back to them
- but the real killed, if you got full castle screen so you could see the defence then you could actually pass on the exact troop numbers to another 3rd party leaving that defence as a sitting duck simply waiting for the info to be passed to a player with a big enough offence
And besides what problem are we fixing here? Having someone reinforce you is in no way detrimental. What do you gain (other than satisfying your curiosity) from knowing who and how much someone is helping you out?