Yep, right in middle. Ideal would be achieving around max 5500 wot rpm with stated load, the issue about dropping 1-2 pitch in size is that you won't know for sure how much rpm will be gained with just 1 less pitch reduction. The rule of thumb that states 150-200 + revs probably does not apply. Real world testing shows to be imprecise and tricky to dial.
We have seen while testing 1 less pitch reduction that on very light applications achieves at wot 500/600 + rpm, on medium light applications 300/400 + rpm, on heavy ones should produce 150/200 + revs. Will need to determine up to which weight is considered light, medium light and heavy. If you go straight for 1 less pitch, probably will hit middle 4900-5500 rpm ? If dropping 2 less pitch probably will over rev ? both cond are wild guesses. Theory dialing doesn't work and could be expensive. A water trial test is mandatory, roll the dice and start with an 18 pitch if available.
Personally preffer over revving, if boating solo while lightly loaded just watch tach closely and reduce throttle to max 5500 rpm. OTOH will benefit carrying more load with better hole shot and reduced throttle than with current prop, but with less top end speed.
Happy Boating