In my younger days, I had a breeding pair of Dempsies with a breeding pair of Convicts. Both pairs would pump out babies all the time... I could never get the dempsy babies to survive, I never knew what would become of them, they would last a couple days, then just dissapear... But the convicts would almost all survive. At one time I had about 300 convict babies from about 6 or 7 different batches.
Anyway, the dempsies and convicts shared a 55 gallon. The Dempseys stayed on the left and the convicts on the right... They almost seemed to ingore each other. But I think this was more the exception than the norm.
I think you should be fine, esp if they aren't breeding. If the Jack's breed, you may have a problem... But keep a close eye on them.