As referenced in the linked thread the rear hub bearings, commonly called rear wheel bearings, need to have a hardened cage. I have encountered bad original Ford rear hub bearings for two reasons:
1. Damaged rollers from failed axle surfaces
2. Rust
Bad cages on new bearings were a big enough problem back in the 90s that C&G had new bearings made with heat treated cages. The
listing on their website even includes the Rockwell C scale hardness of the rollers and cages. I installed a new set of C&G bearings in a 37 sedan in 2008. That car drove 10,000 miles in the next 15 years. Earlier this year the hub were pulled to do brake work on the car. The hub bearings looked as good as when they were installed. I trust the new C&G bearings.