If you create a segment that pulls out data for the two pages (Page A or Page B), then add that segment to your Report Builder call (first screen, top right corner you can apply segments)
Then you shouldn't need to add the pages into the row labels... the day/metric table you build should return all the data for the two pages combined.
However, given some of the metrics you are pulling with Workspace, make sure that you test the segment in Workspace first and that you are able to get everything (sometimes you need to add a few clauses to compensate for click data or some of the calculated metrics - I think you are okay.. but always test first!)