Green terrors can be really, really mean if you get a mean male. For some reson nobody has brought that up. They can be plane nasty. And from my own experiance g/ts and j/ds can be mixed but if the g/t desides to flex some muscle the j/d is usually its first choice.
Oh and someone said they are alone on thinking j/ds are pretty docile. I have had a few over the years and I totally agree. I have a 7 1/2 inch j/d now that backs down from a 3 1/2 inch female firemouth. Its pretty funny to see.