Peter, rear spaces come graded, I think from memory "A" or "B" sizing which should be legible on the spacer. As long as you keep them on the correct side from original you should be sweet.
Edit: just saw they are mixed up. Think your only alternative is to check the spacers, if they are both A or B then no issues but if differnt you will have to assemble the hubs and either measure between each bearing or tighten the retaining nut and get a feel for how much preload each spacer provides and swap them around to achieve equal preload.....if that makes sense.