Why TrinityPower.MinimumRange is setted to 5-30?

[wPrince]

I set Wave of Light as primary, when my monk equips Tzo Krin's Gaze and Incense Torch of the Grand Temple.
But bot always attacks the ememies 16 yards away, not the ememies around the monk.

So I try to change this code:
return new TrinityPower(SNOPower.Monk_WaveOfLight, 16f, TargetUtil.GetBestClusterPoint());

I change 16f to 0f. It seems working.
Is that corrent? Should I change it to 5f?

Most attack skills set minimumRange to 5-30:
SNOPower.Monk_ExplodingPalm, 10f
SNOPower.Monk_WaveOfLight, 16f or 10f
SNOPower.Monk_FistsofThunder, 5f
SNOPower.Monk_CripplingWave, 5f

Why?