If it's a two roller, they work well. Three roller is nicer, but you get the same results from a two roll with two passes rather than one pass.
The European malts tend to be plumper and larger, so the mill gap needs to be opened up more than when milling North American malt. The malt from North America can be milled on the standard setting on my Grain Crusher mill. When I mill Wyermann or Crisp Maris Otter, the mill will stop passing grain after a while because the grains are too big, so I open the gap slightly more the first pass and pass the grain a second time with the standard gap or maybe even slightly smaller than standard gap. The is effectively what a three roller does with one pass. The first gap a lager than the the second gap.
P.S. Watch out for those nasty stones, especially in European malts, they can do damage to the mill. I go slow with those malts so if a hit a stone it doesn't do any damage. I have never seen them in any of Rahr's malts.