Here’s the most credible source of what will you need to do. It’s right here on these very forums in the sticky section.
On PTR I copied the character that did all the requirmenets and a second one that did none of them. I used the second one to go to the embassy and when I clicked on the banner all the requirements have been ticked as completed.
So just like all previous allied races you can do each achievement on a different character.