Warren,
I was able to reach out to the Meraki Product Manager, and he responded with this information for you:
Based on your needs (roughly 3500 teachers/students), we believe our aggregate level switches (MS 425) might be a good alternative. While core switching is not in our portfolio, customers often choose our stackable high capacity switches to address many of their educational deployments. The benefit of choosing this setup is that your entire network will be cloud managed.
Ultimately, the decision will depend on the amount of traffic you expect to see in your system.
Here is an additional resource you might find helpful:
https://meraki.cisco.com/lib/pdf/meraki_datasheet_ms400-series.pdf
~ The Meraki Team