Yeah, many a time I've caught myself saying, "That Hadadezer is an interesting Leader, but not half as good a choice as Jason of Thessaly or Aethelfleda of Mercia . . .
More seriously, I think at the moment the Trade mechanics of Civ VI make it very difficult to give adequate importance to any of the early Trade Civilizations: Palmyra, Sogdiana, or even Phoenicia. There just isn't enough income from Trade early on (mostly because there are so few Trade Routes possible until mid-way through the game) so the advantages of Trade - lots of Gold with which to build your Civ and influence other Civs - has to be obtained by other means, like the 'Gold Factors' built into Mali/Musa which don't rely much on Trade for their effects.
This is a shame, really, because some very unlikely Civs made a good thing out of having Gold as an influencer. Diplomatic correspondence gleaned out of papyrus and other sources show that ancient Egypt, which had access to Gold Mines in southern Egypt/Sudan, was able to extract all kinds of diplomatic concessions out of other Middle Eastern powers (Hittites, Assyrians, Mitanni, etc) by, basically, bribing them. Famously, the most deadly Persian 'archers' were said to be the archer imprinted on the gold 'Daric' Persian coin, with which the Empire bribed Greek politicians - most famously, Demosthenes, who produced his anti-Macedonian 'Phillippics' propaganda essays to earn his pay.
And, of course, Trade revenue allowed Carthage to buy its armies from mercenaries and stand up to the much larger population of Rome for 1.5 of the 3 'Punic Wars'.
It's unlikely we'll see such a major revision in Civ VI, but it would be nice for the next Civ iteration to pay more attention to, say, an Economic Victory and Gold Generation from Trade (which, at least early in the game, also requires an emphasis on Exploration, as in the Phoenician explorations of the Atlantic coasts of Europe and North Africa) which would allow a better representation of the Impact of the great Trading Civs.