The Etruscans weren't conquered, exactly. They were more subsumed into a pluralistic context in Rome and Italy:

"Rome was probably a small settlement until the arrival of the Etruscans, who constructed the first elements of its urban infrastructure such as the drainage system... Later history relates that some Etruscans lived in the Vicus Tuscus, the "Etruscan quarter"" (https://en.wikipedia.org/wiki/Etruscan_civilization)

Pluralism is unity, too. But it's stronger and richer than monoculture. Cosmopolitanism enriches further. We're fortunate to live in such an interconnected age, with such diversity, and as it grows, we'll grow stronger in civic strength and culture.