Which definition do you want?
Romantic = opposite of Classic, in the sense that Classicism is purely intellectual, and Romanticism is purely emotional.
Here's where I was going with this:
Many of you think Tobias was overly-emotional, like this romanticized version of a loner kid. (He wasn't a criminal, remember?)
I don't think they were "stereotypes" in the sense that they were stock characters, but I think each one of them served a role. Jake was the jock turned leader, Rachel was bloodthirsty Barbie who wanted to do good things but got too caught up in the excitement, Tobias was the loner in every sense of the word, Cassie was the nature-lover who stuck to her beliefs, Marco was the calculating fighter who masked his concern for his mother with his jokes, and Ax was the war student who was stranded on another planet to fight an alien war. These roles were fleshed out enough throughout the series to keep them from being, one could say, a bunch of Mary Sues.