Fuller answer: Regimand is good at Grey Wizarding, that's why he made Magister. He's been good at Grey Wizarding for a long time, which has made him very good at it. He's built up a lot of contacts and experience and knowledge over the years. This is what you should expect of any Grey Wizard of advanced age: that they are very good at whatever their job happens to be. The Journeyman examinations are stringent enough that almost all Magisters turn out to be damn good Magisters, and unlike the other Orders the Grey Order doesn't let its Wizards just take a nice cozy sinecure somewhere reading the palms of rich old ladies or whatever, and yet over 90% of them will die as Magisters. This is not a failure on their part. It's not one of those things where if you've punched the clock long enough without punching your boss you'll get the promotion eventually, and if you don't something must be wrong with you. Lord Magister requires more than that. You need to be considered exceptionally loyal, exceptionally able, exceptionally reliable, and exceptionally experienced. Regimand could be argued to tick the reliable and experienced boxes, but his ability has plateaued and the whole conspiracy thing muddied the waters enough that there's some questions even though most of the details of that never got out. If he really wanted Lord Magister he could push himself harder to increase his abilities, do something to prove his allegiances, or find a Great Deed to do to waive one of those boxes, and possibly die in the attempt... but he doesn't want it. He wants to do what he's already doing.
