Hmm...This might be kinda wonky but I feel like if you're gonna tackle this kinda concept in OU, I think specially offensive Pokemon might generally have more of an edge in OU considering the majority of specially defensive Pokemon you see in OU aren't really walls with reliable recovery (You got Chansey, Mew if you wanna count that?, defensive Clefable though with Gunk Shot Greninja now being out that's on a decline, and I guess Porygon2). Most specially defensive Pokemon tend to be bulky tanks or Assault Vest users, such as Excadrill, Heatran, Conkeldurr, Azumarill, so on and so forth. Or a Pokemon that typically is physically defensive but is instead running a SpD set, like Gliscor, Rotom-W, Tyranitar, and the like. The reason why I say this gives special attackers a bit more of an edge in OU is because these Pokemon can be a bit more prone to getting worn down by the presence of special wallbreakers. Since most of them lack actual recovery themselves outside of Leftovers, they rely either on having Wish/cleric support, their own offensive presence to quickly remove threats, or offensive partners who can beat these Pokemon. Compare this to the wide range of readily-available physically defensive Pokemon in OU, many of which have recovery, such as Skarmory, Hippowdon, Venusaur, Ferrothorn, Mandibuzz, Zapdos, Mega Scizor, Slowbro, etc. While I'm not saying physical attackers have a harder time simply because there's sturdier defensive options for taking the majority of them on in OU, I will say that wallbreaking from the specially offensive side can be a bit easier based on this. I still have some opinions but I'm gonna try to not blow all my thoughts here in one post haha. I'll probably make some more a bit later.