Deathstroke and Deadshot is absolutely different, Deathstroke is one of the best hand to hand fighters in DC universe, Deadshot is very weak and slow compared to him in hand to hand fight. Inj 1 gameplay desighn of Deathstroke was kinda not acurrate, he should be pressure, footsie based character with a lot of usefull, effective fast normals and strings with medicore or bad zonning. Deadshot should be a heavy zonner with slow ass normals and strings. So Deathstroke and Deadshot can play very different and unique.
All that freezing things captain cold can do with a freeze gun, Killer Frost can do withought a freaking gun and even more, she is a meta human and has super powers, captain atom is just a man with a gun, he is not even high level fighter, one of the worst villians IMO. Killer Frost gameplay has more potential. No need for captain cold 'cause KF and likely Sub Zero.
Etrigan is a demon with superpowers based on magic, he is very fun, and has a lot of gameplay potential.
Weather Wizzard is basically a male version of Storm from Marvel, controls the weather, which includes lightnings, winds, snow, e.t.c. he has more gameplay potential and he is way more dangerous than captain cold. Liam Makintayre (Spartacus) did a good job playng him in the The Flash TV show. Very underated character IMO.
IMO in fightings scarecrow, captain cold, mister freeze is waste of slot because you should have some powers or being a high level hand to hand martial artist. They're good in a story, but not in the fighting gameplay. But that's opinions, opinions, and that's my, we all have a different opinion about this, and that, it's OK. I'm not trying to make you to love these characters, you started it.