A good example of drag being used from a propeller if fine(or flat) pitch is the Rolls Royce Dart engine on aircraft types such as the HS748 and the F-27. They have no reverse. On short final when the throttles are closed, the propeller blades are at the flattest pitch that they can be while in flight as they are on their low pitch stops. At a typical landing speed they are now creating some drag but not too much at their positive blade angle.
Once the aircraft touches down, a handle is pulled removing the Flight Fine Pitch stop(FFPS) and the blades immediately go to a much flatter pitch but not into reverse. Engines remain at idle. This much flatter pitch creates a significant increase in drag and helps slow the aircraft down. You can also hear the different sound. As speed slows, the effect becomes less and less which of course is worriesome on a very slippery runway.
Pull the handle in the air and you will get a big surprise if you are more than a few feet high. You know they went to fine on landing by lights in the cockpit and I suppose directional problems if one didn't move. And if one doesn't go into ground fine, do not open the throttle after landing or it will get really hot(the engine that is).
So the slower you are, the less effect fine pitch has on deceleration. The Allison 501(at least some of them) had something called beta follow up. As the power was increased, blade ange coarsened to give increased thrust although rpm stayed the same. A pitch stop mechanism followed up behind the propeller based on throttle position. Therefore, if an engine flamed out on takeoff roll, the pitch would be stopped from reducing too much. Otherwise immediately after the failure, you have an engine at a relatively high ground speed in flat pitch causing serious directional control issues. With the beta follow up keeping the pitch coarser, you still had directional control problems but not as bad. Therefore you will have a lower VMCG and have less controllability issues immediately after the failure below V1 but prior to the other throttles being closed.