there are very many levels of seal quality available. The enduro ones are good quality but you do pay for them.
FWIW if you buy standard '2RS' industrial bearings of reputable make (eg SKF) you will get something that is reasonable quality and the seals ought to be better than those you get on cheaper 2RS bearings (which are often not full contact seals even when new, if you look at them carefully). However unless it is a special bearing variant, the grease fill (by type and volume) will be suitable for life at 10-15000 rpm, which means it is a long way from being optimised for use on a bicycle. SKF etc do versions of their bearings with an increased grease fill for lower speed applications (comparable to bicycle speeds), but the grease still isn't ideal for bicycle use. [Such bearing variants won't be stocked by most suppliers and may have to be ordered in at greater cost.] The enduro ones have more, better grease in than that, and better seals (for bicycle use).
Cartridge bearings are normally also specified for fit tolerances; someone with a super-accurate micrometer may be able to tell you if the old bearings had an unusual fit tolerance on them or not. When you buy an 'off the shelf' bearing, you are probably getting a middling tolerance of some kind, which may or may not be ideal for your application.
In the campag 'freewheel body' (strictly speaking it isn't a 'freehub', some say) the inboard bearing is usually retained with a circlip. The procedure is usually to nudge the spacer to one side, bosh out the outboard bearing (outwards), remove the spacer, remove the circlip, then (and only then) bosh out the inboard bearing (again outwards).
In the short run I'd suggest nudging the spacer to one side, and filling the void with gear oil. This may keep the bearings happy for a fair while longer.
In the longer term when installing new bearings, I recommend removing one seal from each bearing (on the side that faces the other bearing) and packing a load of semi-fluid grease between the bearings. IME, even bearings with dodgy tolerances and iffy seals will last a long time like this.
cheers