I couldn’t find a source in Shulchan Aruch to add a Mi Shebeirach for a group of people who require Tefillos , worthy as they may (or may not) be.
During times of conflict in EY, in our Shul, we say a few Kappitlach of Tehillim after Davening followed by Acheinu . Sometimes the Rav makes an announcement requesting all to say Tehillim in the Zchus of all Yiddisheh in EY including the soldiers who are being Moser Nefesh for Klal Yisroel…
Far more appropriate , than a new Mi Shebeirach