It is no longer a viable denomination if it cannot rule itself.
There is no such thing as "a viable denomination" named or called for in Scripture. Denominationalism is an invention of man's lesser and more basic lust for power as applying to religion.
The only viable organization of the doctrine taught by Jesus and His Apostles is the local autonomous assembly of regenerated believer-disciple-priests keeping the commands of Jesus watchfully secure, and ministering to each other in the needs of body, soul, and spirit.
Any widespread suprachurch controlling organization is an artifact of the attempt to wed Platonic philosophy with Biblical doctrine, lending political power by solidarity rather than depending on spiritual power coming from the Faith in and on The Christ.
Denominationalism is Satanic in nature, especially when administered by a two-class religious system of mutually exclusive classes of clergy and laity.
Such a system did not work for Judaism, and it has not worked for man-made organizations claiming to be "Christian," IMHO.