Vlad
Safari takes /Users/[USER]/Applications
It does not create a folder for web apps. This is different from both the listed Chromium browsers and Orion.

However, what could potentially be simplified, if possible, is to create one "Orion Apps" folder (like @balupton's provided Chromium examples) instead of two folders called "Orion" and then "WebApps".
(Unless it's possible and/or ideal to just place Orion web apps directly beside Safari's without a folder)