The position of the Vimuttimagga is closer to that of the Vaibhasikas who include all 4 elements in sprastavyayayatana.
A comparison of the Dhammasangani list with that of the Vimuttimagga shows the important difference that the latter adds 3 items : “rupassa jati, vathu rupa and middha.” Although the visuddhma attributes the heresy of middhrup to ..some (ekaccanam matena) the tika tells us that this refers to the abhayagirivasins. Thus the inclusion of both middh-rupa in both the Chinese version and the Tibetan extracts of the Vimuttimagga is evidence that that the Vimutimagga contains classifications that were rejected by the Mahavihara but accepted by the Abhayagiri Skilling concludes that the Vimuttimagga probably came from the Abhayagiri sect. He notes p200 “these are not minor points.
The Mahavamsa notes p267 -268 that the Thera Sanghamitta , who dwelt at the Abhayagiri told the king that the Mahavihara teach a wrong doctrine and so the King made a proclamation telling the populace that they could not feed any monk from the Mahavihara. The good monks thus abandoned it. The Thera then had the King destroy the Mahavihara and “carried away the materials of the buildings hence to the Abhagiri and by means of them many buidings that were borne away from the Mahavihara the Abhayagiri became rich in buildings. Holding fast to his evil friend the Thera Sanghmitta and to his servant Sona the King wrought many a deed of wrong…then by the ruthless Thera Sanghamitta the Abhayagiri-vihara was made stately to see” Earlier p264 it notes that an earlier King helped to purify the sasana by suppression of a heresy he seized bhikkhus dwelling in the Abhayagiri..who had turned to the Vetulya doctrine and were like a throng in the doctrine of the Buddha he excommunciated them.” It then notes that the thera sanghamitta (from south India) was embittered against the good bhikkus of the Mahavihara and bided his time until the good king died and the next one Jetthatissa died. Then his time was ripe when the younger brother of Jetthatissa (Mahasena ) came to power.