Those new ones you have do appear quite sub-standard. While dearer, I have tried to buy genuine items as I found the boot would stay put so much better than those fitted to the after market types and even if displaced, they would still largely cover the cup well. When doing refurbishments, If the ball and boots are good, rather than replace the whole joint, I'll replace just the cup, which by the way, the originals were a moly impregnated nylon.
Are these balls hardened?
The originals were in an EN8D Grade Steel and Hardened to 52 Rc. The original Ball End had a ground finish.