I kinda think that the Helmacrons add some variety in the series. I know there a lot of other aliens to keep track of too, but that alone doesn't make the Helmacrons unneccessary or worthless Come to think of it, none of the other aliens that weren't introduced in the first book ever had a major, story-changing effect on the series, not even the Howlers. (Okay the Elimist and Crayak did, and I guess the Chee, but still...) If there is life out there, I expect there to be a lot of it, so they didn't bother me too much as far as being in the series goes. They did bother me though, in their own unique ways.