Envisage was designed so that each individual updates their own stats. The purpose of stats is to monitor one's performance, therefore ideally a person is responsible for entering their own stats.
Envisage allows unlimited users for this very reason—a person should be responsible for updating and monitoring their own stats.
This is an important point regarding future updates, as we'll be releasing features whereby the Responsible User will be emailed or sent a text to remind them to update their stats.
In short, no signal individual should enter everyone's stats.
This video further explains the benefits of the Responsible User:
Note that only members of the Owner's Team can update another's stats.