If I had a dollar for every hour that I've spent wrangling over sitemaps, I probably wouldn't still need to work.
Your website navigation is not unimportant. But it's also not the thing that will really do much in the way of directing traffic to your content. That was true all the way back in 2000, when Google was just starting to sell its first ads and social media was still a glimmer in Friendster's eye. Here's Jakob Nielsen:
Web users go straight for content and ignore navigation areas. Limited structural navigation and local navigation still help, but general navigation should be avoided and generic links minimized to the truly useful.
People aren't clicking a bookmark to your homepage and then using your site navigation to find content. Stop worrying about whether things are three clicks from your homepage.
I've used a lot of client money on hierarchical taxonomies. Not on creating them, mind you. On various card sorting and user testing that demonstrate what we said in the first place: human knowledge does not fall into neat hierarchies.