That works for people who are donators and not admins, but because we are tied to Sourcebans (instead of each server having independent control of admins) every person only has ONE account by steamID on sourcebans.
Random example: say youre a trial admin on ZPS, you are in the trial admin group, you are given access to that on the ZPS server specifically, and you have an immunity level of 5 (on a scale of 100). If you were to give them access to another server, it would automatically give them their trial admin abilities on that server, you can't (as far as I can tell the way our sourcebans is set up) give them different abilities on each server because there aren't separate settings for their access on separate servers.
The immunity and group and accesses are all tied to that one account, NOT by server. Vet admins work fine because they get the same level of access on all servers they are admin on, but as soon as you want someone to be an admin on one server, and only a donator on another, it becomes (as far as I can tell) impossible to do.
Now currently the donator group doesn't work anyways, it is a group with 0 immunity (so all admins can act upon them like normal), and a custom flag for the models plugin, but when people who donated and are set to be in only the donator group (like Otter) join the ZM server, they don't have the flag that sourcebans says they should have, for whatever reason, so that is ALSO broken