There's more than just deciding to "round up" a partner
Dan Savage often talks about there not being a "the one"; he says there's a 0.67 and you round up. It's a nice turn of phrase, and skewers the existing myth nicely.
But it has a weakness: its quantitation. It implies that there is a certain set of checkmarks or critieria that a potential partner (or spouse, or primary partner, or mate, or what have you) must meet before they can be potentially considered.
There's a qualitative side to things as well. I propose this complement to Dan's otherwise excellent point:
Choose who you want to be with, not what you want to be with. Then decide how you're going to make it work.
Neither of these should stand alone. It takes an absurd amount of "rounding up" to make someone who is a "0.1" into anything like a "1". Someone who is a partner shouldn't be damaging to your mental health, and should meet a majority of your needs.
Like any good mixed methods application, it's vital that you consider both aspects. And in considering those aspects, you may have to consider - or even change - both the roles a potential partner could fill, and more importantly what those roles look like.
The latter is not harder to do, but harder for people to typically think about, but is that last part of how you make your who work.
We have certain images and ideas in our heads about what a "partner's" role should be. Maybe your idea involves separate checking accounts - or the opposite. Maybe you expect someone who fills typical gender roles - or someone who inverts them. Maybe that person who you want as a partner can't (for whatever reason) do all the things you think a partner should do.
But that just means that you have more than one relationship in your life. Perhaps you have a friend who is a great handyman. Maybe you need to be more flexible in your gender roles. It will vary from situation to situation.
But if all of you know who you want, then you have a shared goal. When you know who, then it is possible to work together to help each other round up.
And then your who provides a why you should do the how.