I think you’d have to go really off-beat! [name_f]Eleftheria[/name_f] & [name_f]Ivy[/name_f], [name_f]Faye[/name_f], [name_f]Florence[/name_f], [name_f]Bonnie[/name_f] doesn’t work. But [name_f]Eleftheria[/name_f] & [name_f]Lavender[/name_f], Libertine, [name_f]Mildred[/name_f], maybe!
I actually see it differently than you, I think I notice the stylistic difference way more in same-gender sets!
To me [name_f]Anastasia[/name_f] is a non-issue that kind of goes with all of the names on your list. (From your longer list, I also think [name_f]Athena[/name_f] and [name_f]Mathilda[/name_f] fit right in with the rest of your style)
Granted, I will say [name_f]Eleftheria[/name_f] would be an issue pronunciation-wise in most of [name_m]Southern[/name_m] [name_f]Europe[/name_f], because most of them don’t have the “th” sound!