As Björn said, a good Aplanat can equal just about any lens for center sharpness - and indeed some will surpass many modern lenses! I have a feeling that Rapid Rectilinears are less super-sharp, but have no evidence for this. But I'm certain that wide-angle Rectilinears are of a different design than wide-angle Aplanats, and that the WAR's have considerably more field curvature and other aberrations.

The exception is the wide-angle configuration of the most common casket sets - they end up with a kind of WAR spacing, and are definitely not as sharp as a "real" WAR (and miles behind a WW-Aplanat).

Casket sets are a nice way to get a complete set of focal lengths including "wonky" wideangle configurations - a 65+75 combo without spacers becomes a rather soft 350mm'ish portrait lens. Something like THIS is wonderful if the shutter is working. Or this one, if you have another shutter option (I use mine on a Speed Graphic).