The word for someone who lectures that "there's a wrong way and a right way" [closed]

I'm looking for a word for a person who lectures others, on a trivial topic, telling them that "there's a right way and a wrong way" to do things.

A couple of words come to mind: "rigid", "finicky". But those don't adequately capture how trivial the person's lecturing is.

Solution 1:

A pedant or being pedantic springs to mind the most as capturing triviality. But also dogmatic, opinionated, or doctrinaire.

Solution 2:

A martinet is someone who demands strict adherence to rules. A stickler is similar.

In both cases the implication is that these people believe procedure should be followed regardless of how little benefit it might have in a particular situation.