Good question:
What is the Resistance?
It used to be those clergy and laity who wanted to preserve the mission and apostolate of the SSPX (i.e., form a new congregation if the old one sold out).
That, by definition, excludes the independents, who, both before and after the crisis in Tradition, prized their independence above the continuation of ABL's organization of tradition (and it especially excludes those independents who have never had any relation to the SSPX or the Resistance bishops, like Fr. Perez and Colletti).
Later, a new approach to the apostolate eclipsed the original vision, favoring independence.
Are these "Resistance?"
Well, some of them are affiliated "loosely" with the bishops, but they have given up on the original purpose of the Resistance (i.e., to preserve Archbishop Lefebvre's approach to the apostolate).
Once upon a time, these had no other option but independence, there being no Resistance congregation set up to receive them.
But that is no longer the case.
There are now two competing visions for the "Resistance:"
One which believes Archbishop Lefebvre's model (Which is the Church's model) is still viable, and one which does not.
So to your original question: Are such as Fr.. Perez and Colletti "Resistance," based on nothing more that disagreeing with Bishop Fellay?
I say no.
And what of those others who went from the SSPX into independence, and choose to remain there?
Are these "Resistance?"
Only in a very mitigated form: They simply want to survive, rather than rebuild.
It's true that ABL often spoke of the SSPX as a pilot light, simply trying to remain lit until the Church recovered from V2.
But this was merely a humble assessment of the SSPX' s "lifeboat" status, not an endorsement for fatalism or surrender to the inevitable eclipse of the Church.
Yet he continued to build and rebuild, and the fact that the Vatican felt threatened enough to try to control him for 20+ years shows that he was not content to merely wait for Heaven to fix the Church.
Some of the final posts of the Syllabus Blog addressed this issue, and I agree completely with their assessment:
However antimodernist the loosely affiliated former SSPX clergy may be, they are nevertheless infected to some degree by liberalism, insofar as they have preferred their own independence to hierarchy and authority (which they now consider to be dangerous), and have preferred to linger rather than rebuild on the basis of a false and/or exagerrated appraisal of the situation in the world and Church.
This is only my opinion, and it should not be construed as an attack against anyone.