You should probably use the other WINS server as replication partners:
http://technet.microsoft.com/en-us/library/cc786754(WS.10).aspxIf you configure one of them to be secondary than I expect oyu clients will constantly have problems and delays, when their WINS queries will change to the other network server and fail for local results and vice versa.
This explains the fallback mechanism:
If the primary WINS server cannot be reached for a WINS function (such as registration, refresh, release, query), the client requests that function from its secondary WINS server. The client periodically retries its primary WINS server.
Taken from:
http://support.microsoft.com/kb/150737