Upgrading to WP 3.3.2 in a multi-server environment

I have a multisite install of WordPress, v3.3.1. I want to upgrade to 3.3.2. The site runs off multiple web servers.

In previous upgrades, I have done this type of work early in a morning before the (many) people who write on the sites start work, in case of problems if I need to rollback to the earlier version (webserver + database server). Also, it minimises the number of superadmin users logged in to the system, in case they feel like trying to help with the upgrade by clicking buttons.

For 3.3.2, as it is a minor release, I was wondering if a change of deployment strategy would work. I would like to take one server out of the load balancer, deploy the changed files, put it back in the load balancer, then take the second server out — and so on.

My concerns:
* Schema changes to the database. Doesn’t appear to be any in 3.3.2, which is good.
* The “click here to run the upgrade” nag in the wp-admin. It’s not impossible that another superadmin user could naively click the button before all the servers have received the new files. I don’t know what issues this might cause.

Any experience of doing this, or tips, would be welcome. Thanks.