A scene like this should be fairly simple to convert into modular assets. I would start by literally removing any geometry that is similar to any other piece. It also depends on how far you want to push the modularity, for example that centre piece (can't remember its name for the life of me) could be made up of 1 piece…
Look at Red Dead Redemption for inspiration. Honestly I think your town is to big to be an "old west" town. Old west towns tend to be on one straight through dirt road with some other smaller buildings around it. I don't think the lamps nor the train in the background fit the scene well at all considering the time period.…