From what I have read about the breeding and hatching of Bearded Dragons, its not wise to help the baby out. Its normally a sign of illness if the baby can't get out on its own. That and sometimes helping the animal can result in illness, weakness, and even disease. If you absolutely have to help the animal, be prepared for it to give you a run for your money. It may live, it may not. From the book, written by a guy who keeps an enormous BD farm, his studies showed that most that were helped from their shells either died soon after, or contracted permanent illnesses that plagued them for the rest of their lives, resulting in shorter lifespan (though a 5 year life reduction isn't insanely that much).
I'm no expert on Leo breeding, but I would assume the same rules would apply. If the Leo gets out by itself, it should be relatively healthy, though being so young they are still susceptible to all sorts of problems.
I had planned to breed my beardies, but my first one died from Impaction, which I didn't catch, it was really sudden, and now the second one may have coccidia from possible cross contamination, which is my fault (I used to be really arrogant).
SO just keep an eye on them, if they get their heads out of the shell, they should be okay, but if they seem to just be struggling to get out and can't put up much of a fight against the shell, it is probably weak and likely to die.
Sorry about your loss.