This has nothing to do with morals, you nitwit. It has to do with canon law and sacramental procedures. If the bar is set so low as to make +Thuc's actions doubtful, then +ABL's sacraments are surely doubtful as well.
Trying to call me a nimwit is only projecting your own insecurity to a theory which you have an emotional attachment to, namely sedevacantism. And an attachment to Thuc for extra measure.
The point, which is not obvious to you, but I will clarify it to those of good will, is the remnant is far more likely in Lefebvre Sacraments than in Thuc line Sacraments.
The "doubt" over Lefebvre's line is not a real doubt, but is simply an opinion. But an opinion which leads to saying that ALL sacraments no matter where they are basically are invalid.
Where as not one theologian would hand wave away like Thuc cultists do, the very real concern of simulating a Sacrament.
On the balance of prudence, one is far safer with the Lefebvre line than with the Thuc one.
The doubt, over Thuc is not a statement of invalidity, it is simply a doubt. The Lefebvre line is far more certain than Thuc and so conditional consecration of Thuc clergy should come from that. Because it's either that, or ALL Sacraments have failed.