Your idea of a cohesive and loyal republic here seems to hinge entirely on the fact that the senate never surrendered, which isn’t nearly as remarkable as you’re making it out to be. Carthage didn’t surrender in the 3rd war either, but they were certainly not a highly cohesive entity at that stage.

During the second Punic war nearly half of the republic defected, and almost all Roman allies turned on them. Including a pro-Carthaginian uprising in Sardinia, and and outright defection of Syracuse to Carthage.

I guess you’re free to interpret things however you want, but “cohesive and loyal” is such an incredibly creative interpretation of the Roman republic during Hannibal’s invasion.