When using a "match chart," you basically choose all the potential matchups you want to allow, and then based on the rating difference, the appropriate one will be chosen. The list of potential matchups for, say, R6 are ones that
(1) add to 11 or 12, and
(2) don't have the big number more than 3 times the low number.
So this includes 6-6, 6-5, 7-5, 7-4, 8-4, 8-3, and 9-3.
If rule (2) wasn't there, the next ones would be 9-2, 10-2, 10-1, and 11-1
For you vs Gorst with the expanded list, 10-2 would be chosen. And the for 400 vs Gorst 11-1 would be chosen.
Rule (2) is there because many tournament directors just don't want anybody going to 2 or 1. For a small weekly event for which people are not traveling far and not paying a big entry, I think going to 2 is fine, and for my weekly 8-Ball tournament I always did R5 with 7-2 and 8-2 added in