You should read the Bhandarkar Oriental Research Institute's (BORI) Critical Edition of the Mahabharata - which is the definitive edition, rather than relying on unsubstantiated translations. When Kripacharya asks for Karna's royal lineage (not caste) to let him take part in the competition, this is what Duryodhana says:
Duryodhana said, “O preceptor! It is stated in the sacred texts that there are three ways to become a king—through noblebirth, through valour and through leading an army. If Phalguni is unwilling to fight with someone who is not a
king, I install him as king in the land of Anga.”
Right there you have it. Different ways to become a King. None based on caste.
Our history has had several, several, instances where "Kshatriyas" have not been kings. There are umpteen people who are regarded as Gods and among the greatest, who do not belong to the "upper castes." The author of the Ramayana, Valmiki, was a hunter - which is also regarded as a "lower caste." The author of the Mahabharata was the son of a fisherwoman, also regarded as a "lower-caste." Shabari, from whom Rama accepted half-eaten berries was a tribal inhabitant from a hunting clan - also deemed to be "low-caste." All these people have been looked upon as great beings, almost equivalent to Gods, and have been worshiped.
So no, if there have been revisionists, it is the ones who have used distorted british translations, and mutilated our history.