the LCA is more agile...and maneuverable....it has a better turn rate...
Prove it. I very much doubt you can. LCA may well be more agile and maneuverable, but you state it as a fact when actually, we simply do not know. Ex-PAF fighter pilots here have already confirmed we do not know the full facts about JF.
According to Lao-Tzu, "To know that you do not know is the best. To pretend to know when you do not know is a disease.
the reason for that is the incorporation of 'relaxed static stability'....are you suggesting that the J-10 should have been based on the 'swept-wing' design rather?
Now prove to me JF-17 is not a relaxed static stability (RSS) design.
JF has large Leading Edge Root Extensions (LERX), similar to F-18, Mig-29 and larger than those of F-16, meaning the centre of lift has been moved forward since the re-design after 2003, shown in the fourth prototype. From what I have read, if the centre of lift moved forward far enough to put it ahead of the centre of gravity then JF is a RSS design.
JF has a composite FBW system - digital FBW in pitch axis, stability augmentation in roll, this means JF-17 could well have RSS in the pitch axis at least. It is worth noting that a source has stated that as of 2007, JF-17 has FBW in all axis - this is likely to be true as it has been stated even on the PAC Kamra website and a Janes article that JF-17's composite FBW system was planned to be upgraded to full all-axis FBW system at some point.
I have also read somewhere that originally, Su-27 had a similar composite FBW system design and was designed to be unstable in the longitudinal axis only, so it is certainly possible that JF-17 is unstable at least in the pitch axis - nobody has confirmed nor denied this as far as I know. If anybody has a source on this matter, please post it.
I don't think anybody is suggesting J-10 should have been a cropped delta like F-16, but it is telling that J-10's wing is a not simply a delta but a delta wing with canards. This planform seems to be superior to a simple delta such as, oh I don't know... LCA? If you disagree, why was Mirage 3 upgraded with two small fixed canards in the Mirage 3NG demonstrator in the early 80s? Mirage 2000 was fitted with fixed canards too. Viggen, Gripen, Typhoon and Rafale, Lavi and of course J-10 feature moving canards (Viggen's canards had flaps that only moved during landing though, I think). Hard to believe that in a time when all deltas have canards, LCA does not need them. I am no aerodynamics expert though.
One more point - I read somewhere recently that LCA needs improvement of maneuverability at high AoA and that a French company is being consulted to help out with that. If that is true, then your claim that LCA is more maneuverable than JF doesn't hold much water considering JF's LERX (made larger in the fourth prototype re-design, remember) come into play at high AoA, causing a "vortex" to form over the wing and provide additional lift.