From what I've seen, combo game is pretty limited in this game. You need to burn meter to do a wall bounce, or be lucky and have an interactable thing next to you.
Take a look at green lantern gameplay vs aquaman. His ermac life force move slams them to the ground. Which leaves us with: string-> life force
That's a terribly short combo. In order to make it longer you need to:
string->ex life force->string->wall bounce and so on.
Makes the game more meter intensive, so dashing isn't as necessary. Though I did notice that Green Arrow could dash and fire an arrow, provided he had charged it up beforehand.
I'm guessing its their overall strategy. Game seems to be very damage intesnive. It is a guaranteed 2 life bars, while MK9 could range from 2-3 and felt slower.