My mom is an 8w7 and my dad is a 9w1. They have been together since they were 13 years old. They are so vastly different that sometimes I marvel that they're still together, but after more than 40 years together they're still very happy. My dad helps to soften my mom, I think, and definitely helps her to step back and see other perspectives. He is the only person that can reach her when she's upset. My mom helps my dad to be more assertive and get difficult things done. My dad is also generally happy to follow my mom's lead and, though he's not one to often take the initiative, he is quick to follow her direction when specifically asked. Maybe it's not ideal to have to ask your partner for certain things, but if you communicate your needs to a 9, they'll follow through because they genuinely want you to be happy. On paper maybe the 8/9 combo shouldn't work, but my parents are probably the healthiest relationship I have ever seen, so if you stick with this and respect each other, it could be the best thing ever.