ahh no need found this on metalink

2. Is audsid a unique key?

Answer
------
AUDSID is unique in case of user sessions. When AUDSID is assigned to a new
session the SYS.AUDSES$ sequence is incremented using NEXTVAL and the new
value is assigned to the session.
In case of sessions connecting as 'internal' audsid is 0, SYS.AUDSES$
sequence is not incremented.


in my case noone would use svrmgrl so guess these triggers would work ok