I love these shows! I haven't considered the types of some of the earlier Arrow characters until now, and it's been a while since I saw them, so they're not exactly fresh in my mind.
Iris: ESE? (definitely extroverted and ethical)
Caitlin Snow: rational, probably logical
Cisco Ramon: ethical, probably extroverted (IEE?)
Harrison Wells: ILE trying to pose as a Fi type
Eddie Thawne: probably sensory... not sure beyond that
Tommy: definitely ethical (probably Fi ego), maybe IEE?
Thea: EIE? ESE? SEE? open to ideas
Moira: possibly Beta rational, but I'm at a bit of a loss here, too.
Quentin Lance: Maybe a Gamma perspective of an LSE?
Roy: ethical for sure (the lack of Te is staggering), SEE?
Slade: idk, probably Beta
Malcolm Merlyn: EIE
Oliver isn't a stereotypical SEE, but it works for both pre and post-island Oliver. I definitely see the Se, impulsiveness, and Fi > Ti. He also has the Gamma tendency to form snappy harsh judgements and hold a grudge. He's not as bad about refusing to let stuff go as ESIs (like Laurel) though. He usually ends up forgiving his family/friends eventually even if it does take a while and he treats them very harshly in the meantime.
In Summary, I think The Flash is a very Delta show that portrays Gammas as being too harsh/dark, Alphas as lacking ethics, and Deltas as being very reasonable and sane. It's both heavy and "soft" at the same time. The Arrow, by comparison, is a very Gamma show. It's heavy and harsh/dark. It portrays Gammas as the heroes and is unapologetic about the constant displays of Gamma severity. I think some of the main protagonists are Delta, but they're portrayed as bumbling, foolish, or weak. The villains are either greedy Betas, Betas with messed up, extreme ideologies, or unethical and/or insane Alphas.