I honestly don't see what's wrong with Superman being in the 4th tier. Look at the names. Are you telling me he's better then those people? If he and say, Rorschach fought without powers, you think he'd take him? Seriously?
What you're selling me that he belongs in the same tier as;
Ares (Marvel), Bane, Black Cat, Black Knight (Dane Whitman), Blue Beetle (Ted Kord), Caiera, Colleen Wing, Drax, Duke (GI Joe), Gambit, Green Arrow (Oliver Queen), Grendel (Hunter Rose), Heavy Duty (GI Joe), Hercules, Huntress, Katana, KGBeast, Kingpin, Matsu'o Tsurayaba, Midnighter, Mister Terrific, Mockingbird, Moon Knight, Mystique, Namor, Night Thrasher, Nightcrawler, Omega Red, Psylocke, Punisher, Revanche, Robin (Damian Wayne), Sabretooth, Sage, Shadowcat, Shatterstar, Shrike IV (Boone), Spider-Woman (Jessica Drew), Typhoid Mary, US Agent, V, Viper (Madame Hydra), Wild Child etc.
Some of these people can be argued to be second or, in a few cases, top tier. Sorry I'm not buying.