I started a power user group a few months ago and it's been wildly successful. I gathered 8-10 of my most engaged and technologically capable users in various positions across our instance. Then, once a month, we meet and I train them on different areas of Workfront that I either could use support on or I'm constantly providing support on (like assisting with role designation and adding users to roles).
They all get homework and report back on how their assignments go. To increase communication I created a space on our company messaging tool for the 'PUGS' (power user group) for everyone to share their struggles and ask questions. As they've grown more confident I've given them more responsibility.
This is how I solved a problem like yours for my own instance. I hope it helps! I'm happy to answer any questions you may have.
This blog is also a great resource: https://one.workfront.com/s/managed-content-blogs/system-administrator-best-practices-knowing-your-p...