I'll take a shot.
It's been at least 20 years since I heard the first complaint from a devoted fundraiser in Australia. She was a lifelong learner, as all top performers tend to be. But she worked at a school. Schools can be presumptuous (unbearable, smug).
And her headmaster second-guessed this fundraiser's informed attempts repeatedly. "That doesn't sound like me!" being a fave dismissal of her direct mail appeals
She asked in the after-session, privately: "What do you think I should do?" Immediate answer: "Find a better employer. This person's clueless and cannot be reformed." Which she did within the year, as she later crowed.
This wasn't a one-off.
The nonprofit world is DESPERATELY searching for competent fundraisers. The nonprofit world is actually, right now, in 2022, BEYOND desperate for such. (I have real-life recent examples.)
THEREFORE: If you, fundraiser, hold your ground with your employer. If you insist: "Let me do what I think I know how to do ... and what I think I have the training to do ... then give me a year, no questions asked. Two years would be better, but ... I know you and the board are impatient as hell. Just let me demonstrate fundraising improvements in 12-18 months ... let me move standard needles ... WITHOUT your demoralizing second-guessing, without harping committee interference."
PS: "If you see no improvements in our fundraising program (and, BTW, that usually takes 3 years, not 2), using standard industry measures, then fire me."
"That's my promise to you. I want to succeed. Just don't get in my way, please. Take the pledge." (Well, there is no such pledge from so-called "leadership," alas. But there should be!)