One of the things I notice when looking at great founding teams is the ability for them to grow and learn quickly. I bet that's @natarius4k's point with flexibility. You can't possibly find someone with all these qualities but you can certainly compromise if you can attest your cofounder is learning and improving every day on the weaker soft skill(s).
Great advice. I especially like the bit about look at their savings. All that said, finding a co-founder is next to impossible. I just straight up gave up on that and focus on product.