In Domino Administrator client's tab 'People & Groups' it should NOT be possible to use menu functions to Replace design or to create a new replica.
Consider the scenario where the human administrator works on 'People & Groups' tab but due to lack of her/his attention (being tired or stressed) administrator thinks that it is a Files tab with mail files (after all both tabs show user names in first column).
Administrator wants to replace design of single user's mail file but instead the design of the server's address book gets replaced which quickly propagates and naturally leads to servers being unresponsive.
Creation of the new replica in the same context can lead to having the second replica of names.nsf on server (while the initial intention was to create a selected user's mail file replica). It is also very undesirable situation that can lead to trouble.
Now, of course it's a human error but I've seen it happen so many times - even with experienced administrators. Needles to say, each time it leads to a disaster.
Domino Administrator client should not be prone to such human error.