I don't personally much like low vents for a backyard-size coop. When it's windy, they kick your coop bedding all up and around; you can't use them in wintertime; and they provide a lot less ventilation than if you had a large portion of one whole wall be just-mesh vent. (Closeable for wintertime if necessary). Make it on the side(s) that thunderstorms don't usually come from, if the coop is exposed to strong storms in the summer and you don't have anything else to keep the rain out. If the coop is small enough that you plan to close the open wall(s) up during winter, then yes you still want high-up vents for wintertime use.
If you have a large portion of one or two whole walls be just open, with mesh over it to keep predators out, then honestly IMO it does not matter too much what side(s) your windows are on.
JMHO, good luck, have fun,
Pat