On the JF-17, that 10m^2 figure is wrong and also misleading for various reasons. First off I don't think it's remotely likely that the JF-17 has anywhere close to the radar return observed on large Russian twin engines designed in an era where RCS management was of less concern. The RCS of an aircraft is neither a static value, it totally varies depending on angle of observation. Frontal aspect RCS is probably much lower for JF-17 than the sides. Same is the case with other aircraft if you look at their RCS scattering charts at 90 and 270 degrees.
If we look at the contributors to RCS from an aircraft, you'll know a little why these singular value are no good for anything other than superficial analysis:
And when radars say the range for a fighter size target (3 or 5m^2) detection range is x km. They are giving you the maximum range at which a target presenting the stated RCS would be detected. The range is also a function of the power output of the radar, the size of the antenna, the gain, and the minimum detectable signal that is above a certain threshold SNR.
With JF-17, we're looking at a smaller aircraft, higher composite usage vs legacy Russian fighters, so possibly lower specular return, sleeker airframe with fewer gaps and kinks meaning less travelling/surface wave and diffraction return, concealed engine blades in frontal aspect that reduces frontal aspect rcs. It's also much smaller, that should contribute to less return even assuming and holding all other variables equal. JF-17 is not designed or intended to be LO, so when if we compare it to other fighters of this class I think it would compare reasonably well or perhaps favourably.
However, even this is just my guess, actual spectral analysis and simulations need to be run on it:
Even then we can't really model for how good the rcs management of the aircraft is vs others when considering diffraction, travelling waves and other returns due to characteristics such as discontinuities and gaps in between surfaces, the return from materials, cockpit, as well as pylons and antennas poking out of the surface.