My suggestions
a. Include Infra Red Signature too along with RCS
Problem with that is, that you don't get reliable figures to say which fighter has what signature. You can only estimate, that by size, the used materials and features like air ducts, the Gripen might be harder to detect. I try to get a base with varyfiable capabilities, that anybody should be able to rate and that could be adopted for any fighter, with publicly available infos.
b. Hard points available for weapons should be considered.
Have that and set 11 stations or more as the top rating, 9 weapon + 1 pod station as the standard for a modern swing role config.
c. Instead of fuel capacity consider range.
True, but the Ferry range would be the only comparable one, since it's generally measured under similar conditions (optimal flight path, maximum internal and external fuel). But one has to set limits for the rating. Maybe > 3500Km = 3 points, 3000Km = 2, < 3000Km = 1
d. Weapons available/integrated should have some weight.
I am updating my mission configs, to compare how many weapons and fuel each fighter carries in a certain mission. Which might be better to rate the fighter, otherwise you would rate the weapons with each other.
But here again, the issue is setting limits what an average, good or very good load would be, for every mission.
For example strike with 1000lb LGBs
Gripen E
2 x WVR + 3 × BVR
2 x fuel tanks
2 x LGB
1 x LDP
Which is a standard swing role config for modern fighters today.
F16 without CFTs would carry the same, with CFTs and centerline tank, it could carry up to 4 LGBs.
An MKI in similar configs, up to 7, while any fighter that can't carry the standard load, not get a rating at all. Gripen C for example:
2 x WVR
2 x fuel tanks
2 x LGB
1 x LDP
No BVR missiles and therfore dependent on escorts.
Thanks will think about that, will be happy to hear more suggestions, from you or others.