UOAs aren't good for comparing wear between different oils. UOAs test the serviceability of the oil. After 100,000 miles of 2 oils (of very different quality and/or viscosity) in identical engines with identical use, both could show consistent 1 ppm/1k miles, but one of them could have far more piston deposits, ring coking, blow-by, oil consumption, seal degradation/leaks, sludge, and varnish than the other. It could also have higher wear that won't show up in UOAs because of the range of particle size the ICP captures and some wear metals getting trapped in carbonaceous deposits as they form. Factors like magnets and bypass filters will skew results.
UOAs also cannot determine the source of wear. Copper could be bearing wear or could just merely be chelation from an oil cooler or brass fitting. Iron could be wear from rings, valvetrain, crank journals, etc... or could be from rust of an iron block. Other forms of analysis like ferrous spectroscopy could better determine these things but now you're getting well outside the scope (and cost) of a UOA.
The only way you can accurately measure wear between 2 oils is with extensively controlled conditions on a dyno with before and after measurements with a profilometer for peaks and valleys on metal surfaces (particularly cylinder walls and rings), adcole machine for measuring cam wear down to a millionth of a inch, and so on. Simulation testing like Te-77 and SRV can give a good idea of that oil's performance, alongside rust, copper corrosion, and other tests.