Yes, you are reading that correctly
The chasis is the same, but, a slight variance in the overall dimensions because of the lack of a front window in the Shadow Cruiser results in a slightly different front cap due to the lack of bracing that is required for the front window in the FunFinder X series.
The Shadow Cruiser, is indeed, a "sister line" to the FF X Series of trailers. The Shadow Cruiser is aimed at the "entry level" buyer while the FunFinder X series is more their "top of the line" series.
If you look at the specs very carefully, you'll note that the FunFinder X model has a front window, the Shadow Cruiser doesn't...the FunFinder X model has twin 30# LP tanks while the SC has twin 20# tanks, the FunFinder X's furnace is 20K BTU while the SC is 16K BTU... If you go to the "Specifications and Options" page you'll find a much longer list of "Standard" features on the FF X line that aren't even options on the SC line.
That doesn't mean that there is less inherent value in the Shadow Cruiser line; just that the Shadow Cruiser is more your basic Dodge series while the FunFinder X is the Chrysler line...a little more bling and a few more "upscale" goodies included in the FunFinder X series. Both are what I consider to be very good travel trailers for the investment.