The Nash is probably built better, but the Cougar should have 4400# axles and 15" wheels at least.
And those are quite different floor plans. The Cougar 21RBSWE has lots of kitchen counter and storage space, dinette in the pull-out, and is only 25'9". The Nash puts a couch in the pull-out and dinette curbside, but is 27'3" and probably a lot heavier.
The Nash floorplan is unique AFAIK. Others have moved the bath to the middle and expanded the kitchen in the rear. Like the Creekside 23RKS (27'6") made by Outdoors RV Mfg (a sister company to Nash and Northwood Mfg, uses Northwood frames).
2014 ORV Timber Ridge 240RKS,8500#,1250# tongue,44K miles
690W Rooftop + 340W Portable Solar,4 GC2s,215Ah@24V
2016 Ram 2500 4x4 RgCab CTD,2507# payload,10.8 mpgUS tow