I’d definitely agree, for a base mesh, there’s certainly areas where some of that resolution / geometry could be optimized. If you’ll be taking them into zBrush, there’s really not much of a need to make them overly detailed in Maya. Just keep them relatively low poly in Maya, then bake out a map from the high-res version.
It’s typically advisable to keep things as optimized as possible. It’s a good rule of thumb. As an example, things like the bottom of your barrels. If the player isn’t going to see them then there’s no need for the faces at the bottom to be there. As such, they can be deleted.
Another example would be the doors and the walls. They’ve been modeled as individual slats. You could really get away without doing that, through texture work, normal / bump maps and the like. That’d shave a large amount of polys right there!