You're viewing this from an orthodox viewpoint, which assumes that the Church, as a system, is running normally. But post V2, it is not orthodox and it is not running normally. One has to assume the worst case in our V2 times. If not, then let's assume the novus ordo is valid and all the sacraments are valid, there is no emergency situation, and the entire Traditionalist movement is not needed and schismatic.
This is not so, my orthodox viewpoint is based on the Church's teaching that it is a sacrilege to repeat the sacrament automatically, that is, without first investigating each and every situation individually. I have no illusions that the Church is in a crisis, certainly not running normally. That whole line of thinking is entirely off the rails Pax.
Because it's the NO we're talking about and the Rite was changed to a NO Rite, it means that all NO ordinations are doubtful, not invalid.
If / when the Church ever recovers from this crisis and makes the declaration that all NO ordinations were invalid, She would then need to declare that all NO priests need to be re-ordained according to the old rite, but until or unless that happens, no trad group can rightfully take it upon themselves to make that declaration.
For all we know, once She recovers from this crisis, the Church may declare another
cuм Ex Apostolatus Officio on all NO clergy and defrock and excommunicate them all, ruling that they can never be priests at all rather than let them be re-ordained back into the fold to contaminate it again. Far as I'm concerned, that would serve them right, but here's you saying to re-ordain them so they can infiltrate the SSPX. See what I am getting at here?
Being doubtful means that some are valid - that's just reality. The Church made it a sacrilege to ordain twice - period. Being sacrilegious to re-ordain is part of tradition, and that is what condemns the idea of automatic re-ordinations.
It would actually be better that the SSPX simply not take any NO priests at all, rather than risk sacrilege by the automatic ordaining of even one NO priest whose first ordination was actually valid.