Different pens, bowls, everything.In this case they have already met, but if you ever get another tortoise the newcomer needs to be quarantined for a several months at least (6+) to minimize the risk of introducing diseases to your other tortoises.
From my research some species of tortoises, like Aldabra and Galopogos actually like grouping together. I may be wrong but I don't think I am, I have wanted a Aldabra since I could say Aldabra lol and have tons of books and videos on the species.To expand a bit more on Tom's reply - tortoises are territorial. They don't want other tortoises within their boundaries, and will fight, sometimes to the death, protecting their space.
From my research some species of tortoises, like Aldabra and Galopogos actually like grouping together. I may be wrong but I don't think I am, I have wanted a Aldabra since I could say Aldabra lol and have tons of books and videos on the species.
That explains why I fight everyone who steps in my yard. Grrr.