I'm the technical co-founder and my co-founder non-technical; he's brought in so many soft skills around process, finance, sales, recruiting, etc.. that I would have (and would still) struggle at to replace.
He's also a domain expert in our field so for me it was definitely the right choice to make.
he doesn't sound nontechnical if he's a domain expert in your field, but presumably he would be even better if he also had whatever technical skills you're saying he lacks, not worse
what i was saying wasn't either of those, but it's closer to the former: some technical people have a proper superset of the skills of some nontechnical people, because that's kind of the definition of “technical people”
while it is true that nobody is both as good at soccer as lionel messi and as good at programming as jeff dean, you can definitely be good enough at everything to start a company. and lots of people are bad at everything. everyone starts out bad at everything
being bad at programming or biology or whatever the relevant technical field is doesn't make someone good at management or bizdev
so don't look for nontechnical cofounders
just look for cofounders who don't have to be technical