Italy should have more cities to represent Roman manpower

[Atilius]

... it was their greater manpower that won them wars most of the time - not superior armies (e.g Telamon campaign the Romans had several armies each of which outnumbered the Po Valley Celts' one allied field army;...

I don't have any great objection to the general thrust of your argument, but you're mangling the facts here. The Gallic army that invaded Etruria in 222 BC numbered 50,000 infantry and 20,000 cavalry (Polybios 2.23).

On the Roman side (Polybios 2.24) there was an Etruro-Sabine army of 50,000 foot and 4,000 horse and two consular armies, each of 25,400 foot and 1,600 horse. One of these two consular armies was evidently in Sardinia when the Gauls began to move. I ought to point out that that both the Shuckburgh and Paton translations are defective here: each Consul had only two legions, not four, and the 32,000 allies were split between the two consular armies (see e.g. Walbank's Commentary on Polybius). Finally, a large reserve force of 50,000 infantry and 3,500 cavalry was stationed at Rome. A number of smaller forces were scattered about Italy and Sicily.

So, far from being outnumbered by every Roman army, the Gallic army was significantly larger than all of the individual Roman forces.