We could use the Reddit approach to Hot (in Reddit's equivalent to /sub):
Show the hottest post
Show the hottest post that isn't in a magazine from which a post was already shown
Repeat step 2 until we've reached a minimum level of hotness
Show the rest in order of hotness regardless of which magazine they came from
Ideally you'd replace Step 4 with something that recursively applies steps 1-3 to what's left over, but since Reddit doesn't do that, I assume it would be too computationally expensive.