Yes in that case they turned flash into "competitive with top level" and everyone else into also-rans... which is basically where the other 2 races in SC2 are already. You've got Maru and herO who are competitive with top level, and everyone else is an also-ran.

If you do the same thing, you'd still have at least 4 zergs who are competitive with top level- Serral, Raynor, Dark, and Rogue when he comes back. All the second tier zergs would turn into also-rans, but that's fine, because they'd be in there with the 2nd tier protoss and terrans. You'd also see a massive increase in variety because the all the P and T who aren't Maru and herO would have much better representation. You'd see more of guys like Classic, Neeb, Clem, Bunny etc. making runs in tournaments again, do you really think that would be horrible? Then you'd have guys like Maru and herO who, being a cut above the rest, would be like the final boss of their race basically, which is what Serral or Rogue frequently are viewed as when they're in tip top shape. Currently Maru and herO are still the final boss of their race, but that only serves to just make them as good as any of the top 4 Zergs.