When I removed the hubs off my 88 XJ they had SKF bearings, the replacements I got from Hagars also had SKF bearings.
So in 1988 SKF was the OEM source for front hub bearings. I change the hubs at 135,000 miles just as a preventive measure. I spun the old hubs and still still were smooth, no roughness.
With the consolidation of bearing companies there only a few companies that even make bearings any more.
From my experience dealing with Aviation bearings there is not much a company can do to make a bearing cheaper and still have it work. Also bearing companies hold tollerences so tight you can mate a race from one plant with a bearing from another plant and have trouble free operation.
As long as it is a name brand bearing company I'd use them on my 88 XJ. I have SKF now, but if the hubs came with Timken, Fafnir, New harmpshire Ball Bearing, Split Ball Bearing or Torrington tapered roller bearings I'd use with without worry.
There just too much liability for make a inferior breaing in today's world. Remember the guy who assembles the hub will also be held liable. I think I'd be more worried about the lube in the preassembled hubs than the brand of bearings they used.