How are you planning to house them in the future?
E.g.: Are both your dragons that you want to keep, or do you only have them temporarily and at least one of them belongs to somebody else?
I know, big enclosures are expensive, but you will need them nevertheless in the future.
My suggestion is: To not buy constantly larger enclosures and in the end paying more as you nevertheless need the large ones one day, try getting their final (large, separate) enclosures as soon as possible. If this is not an option as for whatever reason: I agree with the posters above, in the meanwhile you have to separate them in the tank they are in now. They will start to injure or even kill each other, and at least the dragon who is a bit larger, stronger, more active will dominate the other one and keep it from getting light, warmth and food. It is a natural behavior: When they are very small babies, they stick together to make it more likely at least some of them survive when a predator attacks, but once they get a bit larger they become territorial because in their natural environment, only a large territory ensures they get enough food. In the wild, the increasing aggression and dominance naturally ensures they spread out over a large area. As a pet, they still show this instinctive behavior.