I have been a on the union Executive since 2007 and there is seldom a week go by that I hear of member going into HR and representing themselves in some matter. While at times I can understand the desire potentially for privacy, or embarrassment for what has transpired or possibly figuring you can handle the matter yourself for the most part, this typically results in you being compromised. I can think of only a handful of occasions where people represented themselves that it turned out well, and none of these issues involved a discipline, job performance or bully and harassment issues.
The stewards are trained and operate with a high level of professionalism and respect for your privacy. They are not there to pass judgement on you but rather to represent you and assist you with matters. We try and encourage you to select a steward based upon your personal decision.
Please review article #14.04 that determines when a shop steward should be involved. Article #3.07 outlines when a executive member or a steward may assist.