I think Mitanni and the once large Syro-Hittite state are good candidates. Philistins too.
Levant Bronze age are quite unique. The only population close are Saudis and Yemenite Jews but by a significant difference margin ( 20 % i think).
Modern Lebanese could be modeled by Levant Bronze Age + a steppe enriched Bronze Anatolian population.
Romans are often exaggerated. They settled large armies but their armies were never full Roman especially at the extense of their empire. They certainly added steppe though there is a clearer north-to-south steppe admixture in the Levant now that we have Alawites (coastal north Syrians) who almost join the gap between Lebanese and Cypriots.