The canon of the New Testament was already established centuries earlier.

The councils of Rome, Carthage, and Hippo had nothing to do with the canon.

All the books in the New Testament were already recognized as authoritative by Marcion’s time. This is why Marcion could pick and choose between them as to which he accepted.

Marcion’s decision to excise certain books and edit other ones prompted at the church to publish the authoritative list. His free will editing helped them realize why they needed to make the official list more apparent.

This all took place centuries before the councils you list.