I am not so sure.
When the class, the caste was born, it was not unknown for them to take to arms.
- The first perturbation was by the Achaemenids. That incursion, by then in the remote border lands, the centre of gravity having shifted to Magadha, passed without reaction.
- The second was by the Alexandrian Greeks. Laughably shallow.
- The third was by the Bactrian Greeks. That received as little attention as the preceding one, and there is nothing much in Indian texts to give us a clue. There are only a couple of references in Panini's grammar, where they are mentioned in the course of a phrase illustrating a point of grammar. We learn that the Greeks were vicious and they were valiant.
- Then came the Sakas. Within a generation, they were worshipping in the temples that were being built, donating wealth to religious causes, and getting assimilated.
- Their great foes from the steppes followed. They fell even harder. By this time, Buddhism was widely followed. The kushan became the most powerful advocates of Buddhism until that time. What did that have to do with the Brahmins? Nothing. It had everything to do with their successors.
- The Huns followed. They killed everyone, from all segments of society. Much of the gory descriptions of later events are first encountered in these times.
- However, after the Huns, in the early centuries of a new millennium, before and after the Guptas,new social classes are recorded and become visible and influential. That leads to the inevitable speculation that the Brahmins brought these invaders or the previous two waves to dock into the caste system. It is also interesting to note that caste started to be immutable, no changes possible, system around 800 A D. That was very soon after the north Indian backlash against the Huns. Was there a connection? Nobody is quite sure, although these are widely speculated upon by very serious authorities.
After the Huns, in various waves, India was left alone until the Turks, and then the Afghans, finally the Mughals came into India.
What happened to them is an entirely different story and deserves separate treatment.
So the point is not so clearcut and sharply different, Doc. The pen was influential throughout, and the Brahmins took to arms and were kings right through. For instance, as the succeeding dynasty to the Mauryas.