Yep, never liked this limitation with the inability to mix MX licenses.
As previously pointed you can’t build auto-VPNs between different Orgs. You can however of course build old skool site to site VPNs.
Might take some planning on how you build this one out. Or, if your Meraki is feeling generous they can seriously discount so you can get the same licenses across the board.
Darren OConnor | doconnor@resalire.co.uk
https://www.linkedin.com/in/darrenoconnor/
I'm not an employee of Cisco/Meraki. My posts are based on Meraki best practice and what has worked for me in the field.