RFC 2052 describes use for DNS SRV records. Each entry has 4 parts: A priority, a weight, a port, and the hostname. When multiple entries are returned:
"A client MUST attempt to contact the target host with the lowest-numbered priority it can reach; target hosts with the same priority SHOULD be tried in pseudorandom order."
Smack currently returns the first entry returned from the DNS server, which may not have the lowest-numbered priority, and then will not attempt any other servers since the other entries are discarded.