What is "Montreal"?
First we need to define what we're talking about. Is Montreal the island? The incorporated city (not that that's an easy thing to pin down as towns keep merging and de-merging)?
On a practice level, should this guide cover Ville St. Laurent? How about Ste-Anne-de-Belleview? Anjou?
Ideally, the guide could cover all of "central" Montreal in detail, with district articles covering one or more neighborhood (split up based on density of attractions and size) and then attractions elsewhere on the island either get a catch-all article like "Elsewhere on the Island" or "East Island" (I don't mind if there are one or two like that, at the same level as "Downtown") or, they just get a listing in the main article. I'm mostly thinking of the large parks and one-or-two sights like Grandby Zoo. They could even go under "Get Out" if we wanted to firmly separate the city from the island.
So how many levels do we need here? I'd love to have just one, but it wouldn't be homogeneous-- i.e. some "districts" would be a single neighborhood (like Downtown or the Plateau), but others would have two or more (mostly because they're residential and/or boring). I'd rather not have a whole layer of "east island" "south-east island" "south-southwest island" because a) no one really talks about it like that and b) it would mostly be filler or lists which doesn't make for interesting content.
Here is the current district list, with some obvious groupings:
* St Henri * Atwater