The first proposition here is that the Brahmana is superior to Kshatriyas. The counterproposition is that the Kshatriya is superior. You have said, that the two are united together. A distinction, however, is observable in this.
पूर्वो ब्रह्मोत्तरो वादो द्वितीयः क्षत्रियोत्तरः। त्वयोक्तौ हेतुयुक्तौ तौ विशेषस्तत्र दृश्यते॥