Alliance has had bad luck with getting weapon chests up from the emissaries. Your best bet is running M+ and raids to try to get higher item level drops… its all RNG. My highest alliance toon is north of 395 and their weapons are 370… just bad luck.
Here are some of the communities threads I found - you would go to the main forum page > recruitment > communities… keep an eye on it, because new ones pop up and others that are buried get bumped up from time to time…
Here’s a link.
this one was near the top…