If multiple default email addresses, which one is selected ?

Good morning,

I have email addresses are set up as "default" so that users who are part of the team can use it as "from" by default when answering/sending emails to customers. 

But here is when it gets a little more complex : 

Let say, Bob, Jane, and Mike are all in the teams A, B, C.
When Bob and Jane send an email, I want the emailadresseA to be set as their default.
However when Mike send an email, I want the emailadresseB to be set as his default.
Finally, all of them should be able to change from A, B, or C email addresses. 

Right now it seems that the default one is random (or the first set up?)

Any idea how to achieve this example ?

Thanks for your help