Caprikel
Warlord
Commercial Hubs feel pretty useless when you can build a Harbor instead. Part of the problem is that gold is too easy to come by throughout most of the game, and it's never felt like a limiting factor for me when building military units. If gold was harder to come by, Commercial Hubs would be more useful. It also suffers from having few adjacencies, with rivers being the only consideration to make, so there's no real thinking involved when placing them, unlike the Industrial Zone which became the most interesting and complex district to plan around. I guess there's the Harbor adjacency, but there's not much point in having a Harbor and CH in a city when the main use of a CH is the trade route you get from it. A few adjacencies that could help could be a major adjacency next to Oasis's for desert cities, maybe a City Center adjacency like the Harbor, a canal adjacency would also make a ton of sense, and maybe a luxury resource adjacency since those actually make sense as things to trade.