It is true that the -desktopname switch will automatically send a user to the specified pool.
Use a script to randomize the pool name and substitute it a variable in the View command line.
If pools are named Pool1, Pool2 etc you can generate a random number between 1 and n
-- append the number to Pool to create Pooln
-- substitute Pooln as a variable in the View command line. ex: wswc.exe -desktopname "Pooln"
I am a terrible script writer so I needed help with the mechanics of generating the number and substituting the variable but the concept is pretty straightforward.
The hardest part is getting users to click on the script instead of the View Client icon. In our environment we lock down the desktops so only the script runs at startup and users only see View Client and enter credentials once. In your environment maybe you can substitute your script for the executable in the View shortcut if locking down physical desktop is not appropriate.
