This is one of the joys of online fish hunting. It's easy to list a few rarities, and it's easy not to know what you have. If your exporter says they're Fish A, many won't take the time to confirm that. Plus the fish often arrive tiny, and no one holds onto them long enough to see. You don't get a peek at the fish. You buy off a list, and maybe, you get what you asked for.
Add trade names over Latin names, and it's a lottery. I have two dealers I buy from. One is exact. His knowledge is astonishing, and he studies every fish that arrives at his installation. He's also more expensive. The suppliers respect his edge, and don't play fast and loose. They tell him where the fish are from, or they don't get a sale, and his reputation keeps them honest. Most of the time, he knows the actual fishermen. The other is a super nice young guy who sells what he's sent under the name it arrives as. He doesn't know, and doesn't take the time to analyze basic things when fish arrive. He just started buying Indonesian fish after making his business by only selling wilds. He was selling "Pseudomugil red gertrudae rainbows" at a low price, so I grabbed some for my last order on the assumption they'd be Pseudomugil luminatus. It appears (they're in QT) that they are. When I look at his lists, I hope what I see is what I get. But I also look at closely related and similar species, because I could get them.
I think N. lacortei suffer from their low price. They're harder to get in the wild, and demand is less. If they retailed for $10 each, they'd be around,, but as a low priced tetra, they get overlooked. There are a few cool fish like that. When's the last time anyone here saw a fire rasbora (Rasboroides vaterifloris)? They were once a cheap irregular arrival and I loved them in my consumer days. I haven't seen them in local stores in 30 years. No one wants to order a lot because unfamiliar fish don't sell at the bottom of the price ranges.