Forging Indian philosophical texts

Did Indian authors forge their authorities? Did they need it, given the freedom commentators enjoyed (so that Śaiva texts have been used by Vaiṣṇava authors (see the Spandakārikā) and dualist texts by non-dualist authors (see the Paratriṃśikā) as their authorities)?

What is involved in a religious identity? On the Introduction of Leach 2012

What are the Pāñcarātras? Is there anything like a uniform Pāñcarātra Canon and/or Theology? Or are these texts only part of a constellation which has been made consistent by its later interpreters?