it could work if:
the mazeyness was less complex(so you can see a clear route to the enemy

the pathways were wider so things didn't get trapped/stuck at wreckages and mexxes. if each passageway was about 4 or 5 kbot factory widths (24-30 ??) it might give enough room to manouever.
the trouble with them being too narrow will be that it'll be far too easy to defend against any ground attack ass the attacker won't ever be able to get enough units within range quickly enough (or ever!) to do the damage.
the starting areas were about 4x the area
a symmetrical layout (up/down & side to side) could be good for this one
perhaps a better layout/desing might be to foget the idea of completely surrounding bases/expansions with walls and having them as the only 'flat bits' you can build on in the trenches. they don't necessarily need to be any wider than the trenches themselves, assuming you make the trenches larger.
also think about whether you want the tops of the walls to be buildable or not (eg the pass)
keep it simple to start with until you're happy with the layout
