The scenario sounds like the perfect use case for why we have sections, so it should work. I can't see the entire code so can't really tell, but just based on the couple of lines I see above, those wouldn't render if it actually looks like that.
sections
take an array of objects, each of which is a section, which in turn contains items
array.
Also the #each
clause should have a single template object as its value, instead of an array.
So it should look something like:
"templates": {
"body": {
"sections": [{
"{{#each $jason.users}}": { ... }
}, {
"{{#each $jason.posts}}": { ... }
}]
}
}