You could write your own randomized function based on the Positions contained in the area. Whenever I use randomization, I try to use some sort of normal distribution since real human interaction wouldn't randomly choose any location in an area of tiles. Most of the endpoints would be centered on the exact npc location. This is the same for any mouse clicks, and wait times between actions. It's a bit of work to code it, but well worth it to prevent botting-like features.
Try looking into Java's Random class, specifically their nextGaussian() function, as well as Gaussian (normal) distribution.