You should keep turtle species seperate too. Risk is just as high. I know people that mix species too both tortoises and turtles no problems. But personally I would keep them seperate. Quarantine is also a important step. Even if it's te same species you gotta be careful when adding to a group. I have seen on the forums people losing groups for not quarantine the same speices. I know people that say they lost groups due to mixing speices but they only were assuming idk if they ever got vet work done. Either way you gotta be careful, but excellent thread, good to be aware