IRL turboprops can slow down quite fast because of the massive prop. When at idle, the blades flatten out and act like big speed brakes. Some aircraft like the Pilatus PC-6 Porter are capable of using what’s known as the beta range to flatten the blades even more and slow down even more in flight. This allows for extremely steep approaches and I think the Milviz PC-6 offers this functionality.
In the sim, however, prop drag is not really simulated very well by default. This leaves a lot of aircraft way more slippery than they really have any right to be. To combat this, simply plan it a little further in advance.