No, and here is exactly why.
When you go before a disciplinary hearing board, you are allowed to bring two people as defense witnesses. That sounds like an opportunity, and it is, but who you choose matters as much as what they say.
Bringing another inmate into that room is almost always a mistake. The board is made up of staff, and staff view inmate testimony through a lens of suspicion that is hard to overcome regardless of what is actually said. Another inmate can too easily be seen as covering for you, running a loyalty play, or simply saying whatever you coached them to say. Even if every word out of their mouth is true, the credibility ceiling for inmate witnesses in a disciplinary setting is low.
What actually works is bringing someone from the staff side who can speak to your character from direct observation. When I went before the board, I brought the corrections officer who supervised me at my landscaping job. He walked in and gave a straightforward character reference based on what he had seen every day. The board responded to that immediately because it came from one of their own, someone with no reason to shade the truth in my favor and every professional reason to be honest. They released me from the SHU back into general population the same day.
The lesson is simple. A credible staff witness who has watched you work, follow rules, and conduct yourself well is worth more in that room than any inmate witness you could bring, no matter how honest or well-intentioned that inmate might be.