I thought this to myself, a while ago. What other characters could be in the STARS line because I hate the heroes of that line because there are two Toa Nuva. Tahu is in his Mata form but he still was a Toa Nuva. And then there is Gresh, which was too soon but what other characters could they put as Gresh, there isn't many characters which could replace him.
Here is what I think it should've been like:
Tahu - Tahu, because he is an iconic character of BIONICLE.
Takanuva - Matoro, because he saved Mata Nui and Takanuva took the place of the Toa of Ice. Though, I wouldn't know if it would screw up the story line.
Gresh - Gresh, because there isn't much choice when it comes to the air characters.
Rahkshi - Rahkshi, because I think the design of the STARS Rahkshi is awesome and well designed. Even if the arms and legs don't move.
Skrall - Visorak, because the Visorak are more interesting then Skrall. He just doesn't interest me. The best part of his set is the black Kopaka sword.
Piraka - Piraka, because I just think it was a good choice.
Who do you think should've been in the STARS line?