I'm not sure about the use case above, but I'd like to see strict-order as part of the GUI (all it needs for that is a checkbox that then add the directive to the conf file).
It does though either need a note so say #2 is first and #1 is second or that the GUI inserts the servers into the conf file in the logical order as considered by the strict-order directive. As and when dnsmasq fixes that, the kludge can be removed in pi-hole.