What I'm saying is that I can relate to this comparison between Izzy and Fluttershy. Logically, one would indeed have to say that Hitch is quasi G5 Fluttershy. That's also true in terms of hero ability. But in terms of personality they differ (sometimes very much).
I mean, you have to look closely. At first glance Hitch seems like the typical show-off (including his own photo calendar), but you've already seen that he actually feels uncomfortable in many situations, and even starts to cry when his feelings are hurt. And I don't mean that in a negative way. I like this soft side of him.
Izzy, on the other hand, is a kind of reversed Fluttershy. She seems absolutely extroverted and hyper. Almost Pinkie Pie level. But I often wonder if that's really part of her personality, or just a way to hide her own insecurities and loneliness. Because you can't forget one thing: Izzy is VERY lonely. In her head, things are playing out differently (almost borderline repression, to put it very hyperbolically), but in reality, no (or hardly any) other unicorn cares about her and her "crazy" ideas (unicyling).
So Izzy, like Fluttershy in the beginning, is very much outside the bangs of pony society. Neither really fit in, each because of their own "unique" ways. I think that's what Discord sees in Izzy. At least that's my interpretation so far, but I haven't read Issue 2 yet either.
Hmm... I'd be happy if G5 HAD a slightly more complex undertone, unlike G4. If indeed it does, and I'm not overthinking here.