But see that sort of matchup distribution is kind of unfun for people. It's common to grapplers and pros deal with it. But it's sort of heartbreaking to watch Vangief get slaughtered by F. Champ's third tier Chun just like its annoying to play a character with one frame links against Gief and lose 2/3 of your health for dropping one.
Again though I'm not sure how you make a powerful grappler without doing this. Even in Skullgirls where Cerebella represents a really strong grappler who feels balanced, it's mitigated by the assist factor when she has to deal with heavy zoning and similarly assists factor heavily into defending against her.
Now I don't think it's a fireball thing for sure, some of the rush down characters do do okay against Grundy. flash does okay because his normals are fast and multi hit and ruin Grundy's armor game. And Wonder Woman does okay because b2 is almost a better space control tool than a fireball and her strings move her forward and put her plus on block so they both have to make reads.
Unfortunately even with his standing 3 Grundy decimates Lobo. Because Lobo has really poor answers for armor, a terrible wake up game, and his only advantage of high damage off hard knockdown is done 10x better by Grundy. Plus a whiffed chain or 3 is going to get Mb swamp hands on reaction.
Oh also a ton of Grundy's damage is unbreakable. That can be annoying too.
Do I think he needs nerfs. . . No. But he does kind of make Lobo, Bane, and to a lesser extent Shazam feel a bit pointless.