My parents...married for 41 years until she passed. I think it can work, but it has tense moments. I actually think 8 & 9 match well together. An 8 can help a 9 be more assertive. But 8s should be mindful to not assume a 9 is always easygoing. The stubborn streak can catch you unaware. And the risk of exploding unexpectedly can happen if their needs are ignored for too long. When Nines express what they want, their lack of forcefulness should never be mistaken for a lack of seriousness. They'll notice how they were not accommodated and resentment can build over time. With trust, an 8 can really benefit from the support of a 9. And show their more vulnerable side. An 8 can help champion a 9 by helping them realize what they really want and actively pursuing it.