I have not done the VX wheel bearings yet, but just about every car on the road uses the same principles.
For each wheel bearing there is an inner cup (comes with the rollers and cage assembled) and an outer cup.
The outer cup has to be a tight press fit into the hub. If not the hub will flog out, and you cannot get the correct preload on the wheel bearings.
It is unusual for a hub to go bad, but it can happen in extreme cases like totally stuffed bearings or a dragging brake calliper, but the old bearings would look blue from the heat before the hub would expand.

What degree of looseness is there?? Does the outer just fall in with say 1/16" clearance all round it?? or fit snug but still turn??
What quality bearings have you got?? Cheap Chinese ones have wider production tolerances, so you might have some right on the small end of the scale. Good boxed Timken bearings would be first choice, but there are also other named brands you can trust. (SKF, NGK, TOYO etc)
You can get different sized outer cups to suit the same size inner cups, so I am concerned that he might have the wrong bearings. Might even be a metric vs imperial problem. Easy way to test that is try the same bearing cup in the opposite hub. You would not have 2 hubs gone, so if the bearing fits one and not the other it would give some confidence that the hub is shot.

If the hub is worn there are a few options -
1. New or second hand hub would be the best.
2. Bearing companies do make thin spacers to allow a hub to be machined and the spacer press fitted, then the bearing press fitted. A machinist would have to carefully measure up the hub to determine if there is enough meat there for this process.
3. The hub could be built up by weld material in the bearing seat area, and then the hub machined back to standard. This requires both a welder and a machinist that know what they are doing.

Personally, I hope you just have a dodo mechanic that doesn't realise he has the wrong bearings, but this has to be made safe, so no short cuts.

Good luck

PK