Cant say I have the answer because I've only had 1 relationship and I neglected it sometimes, smothered it others and then did both during some time also.

I don't think you would need to have a perfect match of how much space a persons needs. I think its more both people would be comfortable in their own skins and love their selves enough to give the other person whatever they wanted during that time. Each would enjoy the time together and the time apart. So if my S wanted to go out with their friends for the night I wouldn't take it as personal like she didn't want to be with me. Again, not sure how that fills in when someone has emotional needs being unmet. Maybe the trick is that most of our emotional needs needs to come from ourselves and the partner provides the extra that tops us off instead of filling us completely up.

Accept what is, let go of what was, and have faith in what will be