Couldn't find anything from the last couple years but a quick google search identifies this. I would say this confirms he isn't slow:
Top five fastest players in 2021
Aliir Aliir 34.54km/h
Ryan Burton 34.49
Connor Rozee 34.42
Mitch Georgiades 34.06
Lachie Jones 33.95
I think you will find that the vast majority of AFL players these days are very quick these days. Definitely not as many plodders like there used to be. The game has got a lot quicker, and all players have had to adapt to that. I just don't think there are many slow players these days and those that are get chewed up and spat out of the system pretty quickly.
Running ability is highly important.
Burtons 34.4 was running away from the ball




