The single worst use of a compatibility chart is reverse-engineering a decision you have already made. If you are looking for a reason to leave — or a reason to stay — you will find one. The numbers will oblige. They are vague enough to be flattering and broad enough to be damning.
A Life Path 4 paired with a Life Path 5 is a textbook “challenging” pairing. The 4 wants structure, the 5 wants freedom, and on paper they should bicker themselves to extinction. In practice, some of the longest marriages I have ever read for are exactly this combination, because each partner provides what the other is short of. The chart is a description of the work the relationship will need. It is not a verdict on whether the relationship is worth the work.
Numerology is also not a substitute for the things that actually predict a relationship lasting: kindness, communication, shared values, the ability to apologise. If your partner does those four things and your Life Paths are at war, the partner wins. If your partner does not do those four things and your Life Paths are in heaven, please leave anyway.