Why pay for laptops if they are only going to be used on the network on site? Surely a desktop or netbook with Terminal Services would be much cheaper.
I've never understood this reluctance to let staff use their laptops as they need and want to. Yes it may be the schools, but at the end of the day we're always complaining about teaching staff IT literacy and some folks then go and lock staff machines down so they can barely use them.
Ours are on the domain, staff have local admin rights. Sophos AV updates from a secondary source provided by the LEA, and they are all encrypted with Sophos Safeguard. I also use LANSweeper to report on software installed, and give them all the copyright and virus reminder each term. No one has abused this. Their home page is set to Sharepoint which is in the proxy exceptions list. So on site they log straight in, and when at home they get the Forefront web login page.
Staff actually comment on how much better it is compared to other schools where they were severely restricted.
My father in laws old school (retired physics teacher) locked down staff laptops so staff could only use white listed applications. Anything else had to be trialed by the IT Support department, approved by them and then installed by them. Talk about restricting innovation!