Say two people are talking about relationships A and B.
A is complaining to B that her relationship isn't going well because she and her boyfriend have many differences, that they do not have much in common.
B turns to A and says "Someone might have all the things that we like but if they lack one thing then the relationship doesn't work out. They have to be a complete package."
I think B's phrase is clunky and "A complete package" may not even be the best term to describe someone with all the qualities we like. Can anyone change this phrase and show me how to say the same thing in a less clunky way?