It's important to note the difference between a Node vs a Member, and might help you understand the creatin process..
A "node" is global, a "member" is only specific to the respective pool it's created in.. ie, you can have the same host be a part of multiple pools.. This comes into play at a few different points, but namely from the perspective of the LB method for the pool.. For example, least connections (node) is going to factor in all the connections for that host globally, vs Least connections (member) is only going to factor in the connections for that pool it's a part of..