There is no load balancing function built into the DLP software. So yes, if you tell the clients to connect to server a, then b, etc. they will attempt to connect in that manner. If server a is up all clients configured to connect to it first will, regardless of load.
We are using F5 Big IP to load balance these accross our endpoint servers and one hostname in the package pointed to the Vitrual IP. Symantec frowns upon this configuration but it is working in our environment (30000+ endpoints). The only other solution is to create multiple packages/install scripts and round robin the server names/IPs so that you do not over load one server. This is was not acceptable in our environment with the amount of endpoints we have.