My horse was a showjumper & now does workers - the same with my sisters - so they're well suited to it!! Working hunter is far more similar to show jumping than anything else, so they gp together well!!
I do with my two. With the speed you have to go at in showjumping now to avoid time penalties, the distinction in way of going is being blurred. Although I looked at the video of the lovely Thor someone was kind enough to post on a previous thread winning the HOYS WH last year and was surprised at how steady and collected he went - clearly my two have a long way to go!
I find the jumping in workers much easier than in showjumping and find mine can do a higher course in workers than they can in BSJA - my mare just about manages Newcomers but I mainly do 1.05ms with her yet she will do a county level working hunter at 3 feet 9 and be very comfortable over a 3 feet 6 one.