The spawn points of this two player map are pretty standard, the only exception being that the pocket expansion has a ramp leading to destructible rocks. On the opposite side of the main there is a ramp to a third expansion, with a large ramp leading down towards the rest of the map. Between the third and the main there is a drop cliff that reapers can use to get into the main while bypassing both the pocket second and the ramp to the main. The "fourth" is one of two bases, one to each side of the ramp, with the "fifth" likely being the opposite one. The one on the third's side is easier to defend in general, by use of terrain and only have two entry points by ground, one small and one only slightly larger, while the base on the main's side is tucked at the bottom of the cliff between that holds the main and the natural. This provides vision of the backdoor ramp, and a very short air distance between main, second, third, and fourth. The sixth base is on a large, pride-rock looking cliff that oversees the path out of the third. This has gold rocks, and is obviously very important to not let the opposition control, as it overlooks your main path to the opponent. However, the ramp out of the pocket natural leads to a forking path, one fork leads to the wide ramp that leads up to the gold rocks, allowing Protoss and Zerg to easily sandwich an opposition, with their range units hitting from the lowground in front of the rock and their Zealots or Zerglings coming around the back to trap and surround. I imagine most of the conflict happening here, at this 'pride rock' structure. (Of which there would be two, one on each side of the map). The other fork of the path provides an outlet for counter attacks, leading to a path that is just out of siege unit range from the rock, popping the units out in front of the opponents third from a long, swooping path. This path would be low ground, allowing for the opponent to defend it reasonably easily, but a unit wouldn't be able to help defend this run-by ramp AND the large pride rock structure at once, so an opponent would have to plan accordingly. The final set of bases are tucked on the opposite side of the terrain from the fourth base (on the third's side), across from the small-sized entry way. This base would probably only be used in the most macro-oriented of games, as this is a very open and hard to defend base with little value as far as positioning is concerned (though it is the closest base to the opponents main ramp).
There are 3 XNTs on the map. One in each of the player's third-side fourth, and one in the middle between the two pride rock structures. The two in the player's bases are important because they can peek over to see what the opponent is putting on Pride Rock, but also look into that player's third (so it would be very nice to own as the opponent, as well). The one in the middle looks over a small section of the run by ramp, just enough to see that units are moving through with a little bit of time to react before the army is at your door step.
I hope that at least of that makes sense. Please, if you feel willing, give me honest feedback on it. It might be trash, I really don't know, I've never made a map before. I just had the idea of having bases not only be chosen for their ability to be defended, but also be a hot topic because of how they can be used for offense. I also like the idea that, depending on what units you have, the choice of the fourth becomes more than trivial. Ultralisks are going to be horrible to defend the third's side expansion, but awesome at the main's side, while Broodlords are the exact opposite. It's easy to prevent ling-run-bys in the third's side, but easier to prevent muta harassment if you take the main's side.
I will try to draw up a picture on paper. I just for the life of me cannot figure out the map editor!
Thank you for the long read! If you're interested in building this, please either post here or send me a PM, I'll get you as much info as you need. I have a very good understanding of what I think it should look like.