One of the striking things about the Second Punic War is the repeated failure of most Carthaginian generals besides Hannibal to win battles, even in quite even contests and ones where they actually had numerical superiority. The main exception is Hasdrubal's victories over the Scipio brothers in southern Spain, after seven years of campaigning. However, he had already been defeated a couple times by the Scipios, the expeditions to Sardinia and Sicily failed, Mago was defeated at Ilipa despite numerical superiority, Hanno the Elder was defeated and later destroyed, they suffered several humiliating defeats in Africa, and so on. Admittedly, this isn't a very sophisticated analysis, but it's quite a striking pattern of failure and defeat.
So without armies getting smashed left and right by the Romans, basically just holding their ground, would Carthage have been able to send enough reinforcements to Italy so Hannibal could have a secure base for a march on Rome?