More suggestions...
Add in some more variation in the elevation off in the distance. Some slight hills would do fine.
Make the trench shallower, make it maybe a 2 level trench in a way. One level would be deep enough for free movement safe from blaster fire, the other would be a bt higher up so defenders can pop up and crouch down in long range fire fights.
Add in some ports for MKII Stationary Blasters that the Rebels can use for defense.
Add in the ATAT barges?
"Munchkin: One who, on being told that this is a game about politics and intrigue in 17th century Italy, asks to play a ninja."—
Andrew Rilstone