means lesbians are always going to be top of the pile when it comes to this.

The weird thing is that lesbians aren't actually the top of the pile. Bi women are. You'll notice though that these stats are never presented in a per-partner fashion and are always something like: "experiencing intimate partner violence in their lifetime." So if one group has more partners, they'd have the higher lifetime DV stat all else being equal.

Then the obvious question is "why aren't gay men #1?" Probably a mix of DV not being likely in casual encounters, men reporting far far less, and men knowing that they'll get hit back if they start shit.