Hi there, @MichaelGregg ...
Huh...this is an interesting question. 🤔
I tried replicating what you described in both Classic Quizzes and New Quizzes. You are right...if you put a bunch of multiple choice questions and a matching question in the same question group in a Classic Quiz...and the question group is set to score questions at 1 point each, it doesn't keep the 8 points that you wanted for the matching question. I then tried to migrate my own quiz to a New Quiz. Once I did that, I looked at the properties for the matching quiz in the item bank, and I couldn't even set a score of 8 points for the matching question. So....
I know this isn't maybe the best solution...but what about splitting up your multiple choice questions into two groups of randomized questions and putting your eight-point matching question somewhere between the two question groups? That way, it sort of appears to your students that the matching question has been randomly inserted among all your other questions...even though you know on your end it's really the 10th, 15th, or 20th question...for example. This way, you can keep the 8 points for the question like you want. Again, not maybe an elegant solution, but maybe it would work for your needs?
Anyway...my $0.02 for what it's worth. Hope it helps a bit.