I've taught some people the match... and she's actually free to a lot of characters.
Cyborg, Bats, MMH, Sin, BG, GA, Zod, Lantern, WW, DS, Raven, LL b/c they can completely negate flight and have better midscreen options than her. I honestly think a good Batman, is at least 7-3 not 6-4.
@ general m2dave also made a great point that her downward Mace Throw should have the ability to go full screen corner to corner. The creates chip opportunities and negates a strategy I tell players to do in that match- up (back dash to the corner b/c she can't hit you and whiff special moves faster on purpose b/c down mace throw is too slow to gain more meter and count to 10 and get aggresive as she is falling) Also, due to mace throw's atrocious recovery it needs more chip. Superman's standing horizontal laser has 5% chip and instant recovery, while HG's recovery is by far the worst.
Maybe instead of blocking in the air b/c NRS won't add animations (just being honest)... allow armor in flight for a 1.5-2 secs for a bar of meter or allow MB air Mace charge to MB instantly and receive multiple hits of armor or be projectile invincible (mace reflects projectile theory)
I will write more later.