This (the softwareupdate cli tool) can also be scripted using the 'expect' scripting language as you are trying to poke at bunches of machines at once. I use it to do password changes on our network of 300 + machines. You can include logic to check for availibility of packages first to see if they need to be run, you can us variables to endter the update you'd like to apply specifically, you can have it wait once the machine reboots and log back in to try again. expect will allow you to script ssh and automate login processes so on large networks it is easier to maintain with fewer admins.