Alan Scott and an oversized Solomon Grundy is one of those lay-up 2packs I always imagined would've been in Wave 9. Along with Mister Miracle and Big Barda :,(
I think it's just how DC ran itself at the time. The first series of DC Universe Classics, which released the same year as DC Minimates Wave 1, is endemic of this. Actually, the first wave of Minimates seems more focused on heavy-hitters compared to Metamorpho, The Demon, Red Tornado, and Orion. Many of my favorite DC Super heroes, but far from marketable, recognizable names.
That broad variety and unpredictability is one of the things that makes me love DC Minimates. We got Sgt. Rock for cryin' out loud! A halfway decent lineup for the JSA (classic and modern)! Red Son variants! Blue Beetle and Booster Gold! Yes, there are glaring omissions (BLACK. CANARY.), but I wouldn't trade any of what we got.