You can manage plugins by dropping jar files in the plugins folder. It sounds like you have 50 teams with their own Jenkins which they have administrative control over, leading to chaos. This doesn't surprise me. Have you considered letting your team also manage the plugins and locking them all to a specific version?
Exactly this, we let they have full administrative power before because each team had their own little collection of plugins they needed and we couldn't manage the migration out of the "big" old master while also having to curate their plugin collections.
Our current discussion internally is about where to set their boundaries, remove administrative access and curate a set of plugins we are comfortable with maintaining (and that makes sense for most of the teams).
