Nested scrollbars are generally range anywhere from mediocre to super annoying so I always try to avoid them wherever possible. I would make sure the scrollview on the matchups and the decklist is the same so at least we limit how often that scenario crops up. There's wasted space there where we could fit at least another matchup or two to (1) make it look better and more symmetrical and (2) make it harder to hit that nested scrollbar scenario.