I wouldn't necessarily say he was brought in to replace anyone in particular... he wanted to go home given his issues and the cats were happy to take him in... i'm not sure he will get first crack at that spot though, he will need to be a lot fitter than he was at the end of this season.
Just because of how cheap he will be. Three times in his career he’s gone over 89 so it seems like he could either be a stepping stone or a keeper (with a pretty bare forward line this year). And although he will probably get less mid time than he did in 2018 (due to Shiel and some other additions, young players) he will still likely get more mid time than he ever did at GWS.
Last year he played very injury affected with a terrible preseason and I was always against him as an option given circumstances and price.