Hm so if you got the main retroarch package, the original ROMs are actually in the package, too.
You should load RetroArch.exe, then Load Core (pick the Sega one), then Load Content.
In Load Content, click "Start Directory" or something like that.. it's the first option.
Then click ROMs, Genesis, nhl94.
If you pick "CDL" or something like that, that is not the original game, that's a custom league game.
So at this point the game runs...
And you are saying the Hawks are missing? Can you go team-by-team and see what other teams are missing?