The only way to end up with two users as root is to assign another "user-name" the root "UID". (numeric representation for a "user-id")
If edit/cat (or better yet man) "/etc/passwd" you will see the third field is a number. That is the "UID" field.
The only way to have two(or more) accounts running as "root", is to have two (or more) "user-names" using the root "UID' value of "0"(zero).
Only dead fish go with the flow....
Hmmm, what did I miss?