After the critique, I made some changes to the textures. I went back into Maya and added different materials to the various parts of the model, which allowed me to easily add different textures to each part of the model (refer to the image below). I also changed the model a bit because I noticed that the middle part of the wall was protruding outwards instead of going inwards.
I used the brick material for the triangular edges on the top portion of the model and added some height maps to give it dents and bumps. For the pillars, I used a brick generator to create the brick texture and then add a fill layer for color. The pillars also have a height map and some grunge textures I created by painting on top of the color layer. I also added a brick generator to the arch texture set and the main wall (the brownish tan part). They also have a layer dedicated for height variation. The olive green edge is essentially a color layer with a bit of bumps and scratches.
