Why is Fabius (Quintus Fabius Maximus Verrucosus) given so much credit for winning Rome the 2nd Punic War? He decided Rome had enough manpower to shadow Hannibal's army without engaging it while other Roman armies put down the italiens that changed sides. And ultimately he was right.
But... he didn't really figure out a way to beat Hannibal on the battlefield. He came up with a working plan than involved not fighting. Anyone who realized that Rome has a decisive manpower advantage and Hannibal can't threaten Rome itself should be able to do the math.
If Fabius was never dictator, Rome would probably send armies to put down the traitors and every year another army to fight Hannibal directly, which would probably predictably fail (actually Varro at Cannae might have had the right idea to fight where terrain can't hide enemy troops and the Roman cavalry which could prevent a double envelopment was only defeated for silly reasons, but let's say his successors fail too). And that would go on year after year until Rome takes back the walled cities and forts in Italy one by one. Hannibal's ability to produce wins will decrease as he is forced onto a smaller area to feed his army and when the Romans realize capture means execution.
But... he didn't really figure out a way to beat Hannibal on the battlefield. He came up with a working plan than involved not fighting. Anyone who realized that Rome has a decisive manpower advantage and Hannibal can't threaten Rome itself should be able to do the math.
If Fabius was never dictator, Rome would probably send armies to put down the traitors and every year another army to fight Hannibal directly, which would probably predictably fail (actually Varro at Cannae might have had the right idea to fight where terrain can't hide enemy troops and the Roman cavalry which could prevent a double envelopment was only defeated for silly reasons, but let's say his successors fail too). And that would go on year after year until Rome takes back the walled cities and forts in Italy one by one. Hannibal's ability to produce wins will decrease as he is forced onto a smaller area to feed his army and when the Romans realize capture means execution.