Thompson suggests, I think the safer path out of the gate is to have me in control of creating the new sites as we have had some experience of naming spinning out of control in inappropriate ways – these are middle school students, after all... 😁.
With the functionality of the 'friends' login I have been able to do this setup, handing over the reclaim codes to users. Earlier, when I set up group wikis with Google auth, I did the wiki setups as a 'pre-claimed' site, then sent the wiki URL over to them for claiming with their Google login.
.
We have explored various ways to provide preset environments. These include default-pages, preset-neighborhood, and pre-claim-configuration that Thompson recalls. There might be another way using export.json in ways it wasn't originally intended.
1. I created a site which had the pages I thought each member would want as a starting place. starter 
2. I saved that site to a file by downloading http://starter.ward.dojo.fed.wiki/system/export.json
pages/members-starter-kit
3. I dragged that file back to here which then opened for me the ghost page: Import from export.json
4. I dragged from that the Importer item which you see here, ready to create new pages.
5. I created another new site by whatever means I had available. Here I had Register New Site or variations.
6. I drug this very page into the new site and starting instantiating pages there from the Importer. started
.
Recall that export.json was intended as a backup mechanism but here is used as a rubber-stamp for making new sites. There are surely many variations of this workflow that will create various levels of uniformity as might be required in a given situation.