We really only have one game as a reference point of Serong playing as the number one Freo mid against the Dees and that's rd 11 2023 where his DE was a bit off that day and he still notched 93 SC points.
2022 he played two games against them but his CBA % was 48 and 52 for those games, so not a full time mid. In 2021 he did hit the ton against them off about 60% CBAs. Of note he was 20 years of age then, and he was a year younger when he still went over 90 against them in 2020 off about 70% CBAs (the pandemic season).
The Dees are one of the easiest matchups for inside mids over the last 5 games and Serong gets to play them twice on the run home: Freo have a good run home overall for inside mids.
I have one reservation on Serong but I'm looking at bringing him into my team at some stage regardless of that reservation after his bye.