Well, Bae’s right in a couple of ways about Rumple and Hook being alike–one of them being their shared taste in women :p And with the Lacey personality added to the group, it is clear that Milah, Cora, and Belle do have some shared personality traits along with superficial physical similarities. There’s the thirst for adventure that Belle and Milah shared, and the desire for power and respect that drove Cora and Milah, and a lust for power that Lacey shares with Cora. And all three of them are intelligent and have a slightly rebellious inner strength. Their differences are huge–but one can see why they might all have found themselves in a relationship with Rumple. Hook’s relationships with them are all different, of course, but the only person we’ve seen teamed up with him for longer than Cora is Smee, and he does see Belle as desirable when he’s not looking at her as an extension of Rumple.
Keeper of Belle's Gold magic, sand dollar, cloaks, purple FTL outfit, spell scroll, library key, copy of Romeo and Juliet, and cry-muffling pillow, Rumple's doll, overcoat, and strength, and The Timeline. My spreadsheet: https://drive.google.com/file/d/0B6r8CySCCWd9R0RUNm4xR3RhMEU/view?usp=sharing