With Git I’m pretty sure you can literally just add a new remote to a completely unrelated repo, fetch it and then “merge” any branch from the other two into th

With Git I’m pretty sure you can literally just add a new remote to a completely unrelated repo, fetch it and then “merge” any branch from the other two into the new mono repo (ie. git checkout master; git merge other-remote/master). If all your projects are otherwise in a top level directory inside the monorepo this should merge cleanly and then can just live beside eachother in the checkout.