It's exactly what QF did for all those years in their very successful cadetship that generally only the most intelligent guys got into.
They flew a metro or the like with skippers, pearl, Airnorth, macair etc and when they had been there for a couple of years with over 1500TT they were offered a backseat in the 744.
Whilst the flying is more complex in a turboprop due to the nature of the flying, they are easy to slow up and don't have a couple of hundred people plus behind you.
You can do amazing things in a turboprop, 1:1 decents, barbers pole at 5nm and land with a stabilized approach.
You can't do that in a jet!