This and https://diataxis.fr are about all the training you need. Beyond that you just need to organizationally commit to improving your docs. You yourself need to be the leader to keep reminding and explaining to stakeholders why it's important. Or else entropy will get you just like anything else in life.

A good concrete milestone is to create a spreadsheet of doc coverage. The rows are your key use cases and the columns are "tutorial", "guide", "explanation", "reference" (see Diataxis). Take a snapshot of your starting state. And then take a snapshot of your ending state (hopefully with more doc coverage for all your key use cases. It's a nice and clear story to tell to stakeholders. Explain the 4 Diataxis doc types to your stakeholders (basically just repeat the message on the Diataxis homepage). Most people intuitively get it and agree right away. And then you show them the before and after. "We started here and now our docs are much more comprehensive and here's a detailed breakdown to help convince."

I am a professional technical writer (edit: removed my current role because this is supposed to be my anon macro investing account... facepalm)