How does SMS work for multiple phone numbers and different carriers?

[PMVX]

Does it have to have a corresponding carrier per phone number in the right position?

ex:
1111111111 = ATT
2222222222 = Bell
3333333333 = Sprint
4444444444 = ATT

Do I put in something like this?

PHONE_CARRIER=ATT,Bell,Sprint,ATT
PHONE_NUMBER=1111111111,2222222222,3333333333,4444444444