The Latins were not the only ones in Italy guys
The Greeks could prove instrumental in working with the Samnites, Vestini, Umbrians, Etruscans, and Italian Celts in crushing Rome during the otl Wars of the Italic League...think the Napoleonic Wars scenario, but with Rome as the budding French Empire.
Rome is like imperial France, The Samnites lead the Oscan and Umbrian tribes like Prussia in Germany, the occupied Sabines and Vestini play the role of the Iberian Kingdoms, the Etruscans can be Austria...
Who's missing?
Only the pivotal, powerful, powerhouse in a geographically close but advantageous position...a good Britain proxy!
Why not Magna Graecia?
Magna Graecia (Britain)!