Yep. Alice is basically apart of every major arc. From the frat party, to the Klaus Arc, Jake fight, joining HERO and then the Battle of Diamonds. She's ever presence which means she can exert her dominance and stake her claims on the MC.
I slightly disagree on the Tiffany bit though. She's actually established enough that she's basically our Ice Queen. We plotted with her, worked together to fight the Minyaks, infiltrated HERO, took her virginity while she gave us a heads up about HERO and then there's her wedding where we cucked her husband. She's also up to no good again, which will likely include us. So I would say Tiffany is pretty present, at least compared to the rest of our women.
After Alice and Tiffany, it's basically Emily, Liz, and Amber in 3rd place, in terms of screen time. Maybe add Brianna to it as well. After them though, this is where the fling comment comes into play and some might disagree but Ella is head fling. She's barely around, she's hardly committed to being together while preferring to be our stalker. Then there's the constant plotting behind the scenes from her. She might as well not be a love interest with how absent she has been. Though, I'm sure that'll change.
I agree with what you said about joining HERO too early though. It's what disrupted most of our women's scenes the most. Especially since some are human or too weak to be involved. That said, we do get more time to develop the ones that were in game for a very long time like Alexis. She predates Demi, Angelina and technically even Tiffany and Brianna, if you count the Dead End. So it's not all bad because I'm finally getting my superhuman waifu.
All that said, no one beats Mommy 4th. She's literally linked to our soul and is always with us. That's why she's the best!