I don't think that the motivation for not giving an option to managers is "is already too colorful"..
Surely we can say that it will not be a very important thing for the game, but I do not think it's too complicated to do.
During the season a team can become bots at any time, not everyone has a lot of time to follow every single page of the league in which that data is available (even this is a flaw in my opinion .. just add under the name of the manager in the team page the last login made by the user ..)
Having a complete overview of who you are dealing with is also a right for those who are able to spend less time in front of the screen ..
The login date under the manager's name would also help small national coaches to monitor teams that have interesting players for national teams.