A few of the standouts from the Swedish league have come to the Championship recently so highlights the sort of level they're at.
Priske, Walta, Henriksson, Zetterström, Dovin and Eile (via the MLS) to name a few. Competent footballers but not necessarily stand out players, or at least not yet.
Priske who came on for Birmingham was Djurgården's top scorer last season but might be better judged after a proper preseason with their and our season out of sync.
Anyone who is half decent over there soon gets snapped up by sides across Europe pretty early on. I'd say that anyone over the age of 25 who is still playing in the Allsvenskan probably isn't good enough to hack it here or they'd already have gone. Viktor Johansson was at Villa at 16.
Look out for a few joining Middlesbrough next season, especially if they don't go up.