I think if you're writing stories set in actual historical or contemporary settings, your names need to fit the time period or locale. But if you're writing fantasy or sci-fi that isn't too 'recent' earth-based, you can go your dinger. One of the most prolific name-generator authors I've ever encountered is Jack Vance. I think he had a great deal of fun with that aspect of his writing, and it shows. Some of his names are nearly unpronounceable; others fit perfectly, and many of the unpronounceable ones still became strongly indentified with the characters. It is his sense of fun with names that made his 'naming' stand out ...and made his stories fun to read.
In what way? The key to retention is ... ... ... repetition! If you've seen Star Wars there's a bit of a cult following on one pilot Porkins. Then there's one character named after the old speaker of the house and the sci fi ray gun (yes, he was a villain; yes, it was in the prequels; no, it has nothing to do with the Disney ones...) Regards, sarka