I think some similarities with a potential partner are important, but so are the right differences. Who really wants to be with someone exactly or very similar to themselves? How boring might that be? Not because the two individuals are boring, I’m sure for the most part they would not be. But why would someone want to spend a long time with someone who doesn’t ‘challenge’ them, in positive ways that is, based on differences of thought. Would you as an individual ‘develop’ as you go through life with someone who is exactly the same as you are. Where is the variety and excitement in that?
I deal breaker for me would be a woman who seems incapable of taking my brain out for a walk; on a lead or otherwise, I don’t mind. I would want a partner to be able to take my brain out for a walk too.