Thats where the keyword comes in, this game is BASED on.... not an identical clone off the original DB/DBZ, if at some point they'd have to work something out to keep the balance between classes/races then i think that that is a reasonable compromise. I'm not saying that they should step off the basis set by the anime/manga, but the simple fact that we haven't seen all namekians/humans could already be used as an 'excuse' to add something else. Some reclusive namekian that worked to hone some special skill could already open up some options for another class, even within the current healer/summoner/fighter 'boundary'.
The trick would be to find the right balance between original and inventive.
Humans because they made the game...did I do it right?
on topic Namekian because they can heal.
Humans don't make a game. Humans are the race most people play because they are humans. (presumably, anyway. :rolleyes:) What makes a game is how it plays. However, for people who happen to love everything there is about Saiyans and Super Saiyans, I suppose Humans would make the game for you.
And without us, you'd all be doomed because of that. :p