Earlier quoted context omitted.
> convincing people I thought you didn't want to be burdened with selling ideas, but just wanted authority to implement them without convincing people.
“Selling ideas” is not related at all to demonstrating the technical merit of ideas. They are completely unrelated things.
Unless the requirements are brain-dead simple, you'll need to sell at the very least the criteria on which you're measuring technical merit: is a latency number a hard requirement, will it scale for x of years, will it be buildable in y months or years.
At least some of that is going to come to convincing someone you've done your homework even if they couldn't make a better decision right?