Hi and welcome! CAN they live together, the simple and answer is yes. SHOULD they, no in my opinion mixing species is not good. Are you thinking of adding a tortoise to your current one? If so, you would still need a second enclosure atleast for a quarantine period.
In my opinion different species of tortoise should not live together in the same habitat.
Something else to think about is the fact that male tortoises fight...sometimes to the death. If you get two male tortoises you will end up with two habitats anyway. And if you have a male and a female, you will have the male pestering the female continuously and end up having two habitats.
Yah. I agree. Just if so I was gonna get this Greek tortoise that I felt bad for. But I didn't want to spend like 1000 dollars on it. I can't afford that right now thanks for the info!