Here is a source proving that aircraft radars can infact detect Cruise missiles, now of course these are smaller, and also usually use a jet engine which makes it recognizable. We probably both knew this already, but the fact is that modern AESA radars are easily abled to detect a small cruise missile. Your point is that you think that AESA radar could not detect a smaller missile coming head on at it while ALSO providing a strong radar return. Have we actually forgot that AMRAAMs themselves have Home-on-jam capability? Not to even mention AESA radars lmao. But even without this its actually stupid to think that a radar could not pick a missile from headon just because of “low rcs”. you realise that looking at a plane from +100 km would make it as small to the radar as the missile at closer range. I think you think too much about “facts and data” and stopped thinking with your actual brain. I can reinforce this point by looking at your post history which basically proves your full time job is posting on war thunder forums.
Even more to add, we know that ground based radars can detect missiles easily, even mortar launched grenades. With common sense we can verify that airborne radars with similar capability are able to do more or less do the same. Not only is information about this subject very rarely publicly available, but it’s most likely also not researched enough, since in reality things are usually different enough for this not be a cause of concern, thus no direct information about this is present.
That is why most of the time games like war thunder have to make intelligent assumptions about subjects