From the ones you've singled out:
Lucy reminds me of "loose" too much ("loosey-goosey"). Dinah is like I'm dining. Also, a bit like dying. (Diana runs into the latter sometimes, but that bothers me less. Not as keen on Diane, though.)
Gertrude, Margaret, and Olga all have G sounds that are very harsh to my ears. I really don't like Gertrude's "Gert" or Margaret's "grit." And Martha... just... that "marth" syllable, said in an American Midwest accent that really hits that R, is wholly unattractive to me. It genuinely reminds me of John Candy in
Spaceballs telling people, "My name's Barf. I'm a Mog."
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Please rate my personal name lists:
www.behindthename.com/pnl/69381www.behindthename.com/pnl/69381/117507www.behindthename.com/pnl/69381/109399www.behindthename.com/pnl/69381/132018
"If you wish to make an apple pie from scratch, you must first invent the universe." - Carl Sagan