Why the Roman Republic won - manpower or mobilization?

[Darius.D4]

I think that for example the Celts had superior technology to the Romans even when comparing only the metallurgy. But mostly the victory and the supremacy of the Romans had come initially from a superior political and military organization, combined with an iron discipline. Never from superior manpower, superior economy or the quality of equipment.
In the end this was a novel invention at the time(in the way how the Romans implemented it).

I think that the best example ever were Cesar's wars in Gaul. When Vercingetorix had besieged Cesar, his army was so uncontrolled and undisciplined that parts of the army, each lead by different chieftains attacked the Romans not only separately but also on different days.

[Common Soldier]

I agree that Roman victory came initially through superior political and military organization.

But a factor, which might be related to economy, was the Roman ability to recover defeats. Destroy one legion or 3, as at Cannae, and the Romans could raise new legions and come back and defeat you. While this resilience was mostly due to organization and discipline, being able tap the resources of the economy did play a role. Rome was able to utilize the resources of its economy to raise legions as needed in a way its enemies seldom could. A single battle was seldom enough to defeat the Romans, but a single battle was enough to defeat the Cimbri and Boudica.

[Cyclops]

I agree that Roman victory came initially through superior political and military organization.

But a factor, which might be related to economy, was the Roman ability to recover defeats. Destroy one legion or 3, as at Cannae, and the Romans could raise new legions and come back and defeat you. While this resilience was mostly due to organization and discipline, being able tap the resources of the economy did play a role. Rome was able to utilize the resources of its economy to raise legions as needed in a way its enemies seldom could. A single battle was seldom enough to defeat the Romans, but a single battle was enough to defeat the Cimbri and Boudica.

Yes, the Romans could produce a decent army with decent leadership, and then do it again. They had the manpower, and a system that produced a stock of leadership candidates with adequate experience and opportunity.

Many tribes, polities, alliances etc could, produce a decent army or a brilliant leader and while the lived they seem invincible. The Mongol system survived two generations with two unbelievably great leaders, then slowly shriveled. Makedonia had a superb state builder and great general in Philip II, then a superb general and okay state builder (I mean it only fell apart after he died) in Alexander III. Romans could afford to spam armies at a genius like Hannibal because eventually something was gonna stick.