Ordering Users for use in view
If I haven't misunderstood your question and you're using Views, you could simply sort the view by your weight_field and then just assign the right weight parameter to the user.

If you prefer some kind of drag and drop functionality (which in my opinion is easier to manage than weight) you could use Draggable Views, this module will allow you to have a view where you can order your users display, a good tutorial I used as a first timer is this.