When going slower than the normal Ref+5 that an airliner would do, ROD is more effectively controlled with power, which is what the Navy does. Even I transition to that technique in my 185 when the necessity for going slow into a short strip is required. However, when increasing speed from the backside is necessary, then power comes to the rescue. Pitch only isn't enough.
In normal operations with an autopilot, the A/P controls pitch/glideslope and the autothrottles (if equipped) control power/airspeed, and of course, a combination of pitch and power is a blend for maintaining speed and profile.