Paul, battery powered devices (child devices) have a single parent that is a router or hub/router. Their parents (the routers) do the routing for them and the traffic may have multiple paths to travel. That is why you see multiple routes between routers. You wont see a child device connected to multiple routers, they only have one parent. However, a child device can re-home its-self to another router if that router is down and another one is available.
So if your “thing” is a battery powered device its traffic will be handled by a router that can take advantage of multiple routes. It is a little confusing because a “thing” in the SmartThings cloud can be a child device or a router.