In my most humble evaluation of the Church today, it seems to me that we now have in the Latin Rite (this commentary excludes the Eastern Rites) three branches.
For simplification purposes, I will describe them as the Latin Rite of the "past, present and future."
For lack of a better description, we have the Rite of the past, exemplified as the backwardists, represented by the SSPX. They simply do not accept Vatican II and prefer the Church of Pope Pius XII but up to a certain year, like 1955 before the liturgical books experienced some tinkering.
Then we have the Rite of the Church of the present interpreting Vatican II in continuity with what preceded. Thus there is a bit of backwardism and forwardism in this Rite. We can say that Pope Emeritus I also known as Benedict XVI is the head of this Church of the present as His Holiness is still living and at the Vatican to boot.
Then we have the Church of Forwardism headed by Pope Francis I. We know where this Rite of the Church is going, the way of liberal Protestantism exemplified by the various branches of Anglicanism. It is the Church of the culture and anything goes as long as cultural dictates it and what people believe confirms it.
Each of these three branches need a pope. Thus we will have one Latin Rite with three popes.
Technically we already have two popes, Pope Emeritus I for the Church of Continuity and Pope Francis I for the Church of Forwardism.
I would recommend that the SSPX join with the FSSP and other groups that prefer the Church prior to the liturgical changes of 1955 elect a pope from their number. That pope could well be named Pope Pius XIII.
Thus, one could pick and choose which pope and rite they will follow, but still be a member in good standing with the One, Holy, Catholic and Apostolic Church with three popes.
This commentary must be spirit inspired!