I got no idea of course what Keim's sources or access is. But I do agree with a variation of Cooley's point which is he doesn't trust one source or two, he will hit it via multiple sources-angles because one person could be off or have an agenda. Listening to his podcasts, an educated guess would be I think he's accurate because he has give or take 4 angles. Someone in the FO, someone from the coaching staff, an agent or two, and a source with another team or two. It's a good conversation because I've never thought about it before but thinking about the occasional times Keim hints at his sources in podcasts, it feels like this.
I am used to the hey Keim has finally lost it narratives over the years and lol I can't remember everytime it happened as to the narrative. But the more recent ones were people were annoyed on ES when Keim said they preferred Daniels over Maye -- a lot of Keim trashing happened back then and some just didn't buy it. Ditto the Ben Johnson stuff referenced here. Ditto the Quinn stuffed referenced here. Heck just a little while ago some thought Keim was wrong and spitballing on the idea that Blough had a good shot to be coordinator.
As for what Terry's agent can gain by him pushing his agenda.
A. Making the agent look good for starters. You have the narrative going on at the time from some especialy among the local media that Terry's agent is delusional and isn't serving his client. How about trying to reverse that PR in the agents favor and make the case that its Peters who is the bad guy who is low balling.
B. Same point but on behalf of Terry.
As for what Kliff's agent can gain by pushing that story.
A, Yeah talking to any owner who wants to hire Kliff AFTER being fired is a bit weird as to selling that to your fan base, so the 5-12 team just canned this coach in a lower position and we want to give him the top job here! So lets get a narrative out that the firing was BS. Quinn loved him and never wanted him to go. But that dysfunctional Washington team with the psycho power hungry GM foisted the firing on the coach. So in short don't be botherd by the firing because it wasn't a real firing.