He's a true Thuc line bishop... he receive episcopal ordination from Bishop Bendinfield in South Africa.
He's a valid Thuc line... no doubt... the popular Thuc lines in America are more known than the ones outside of the New World.
Are you sure it wasn't Bp. McKenna who consecrated Bp. Slupski?
My first exposure to then-Father Slupski was in 1989. The outcome was not very positive, and a traditional chapel was closed within 4 months of his arrival.
BTW, he is a Redemptorist. I've never heard anything about his morals, which, despite the disagreement with him, I'd have to say are good, Some of those he's ordained and/or consecrated, however, I could not say the same thing. It has no bearing on him, other than he hasn't been prudent in ordaining and consecrating.