Not necessarily. Luneau is still only 20, has plenty to learn even if he has more ultimate upside. Helleson is 23 ... more physically mature, has a full pro season under his belt. Just more ready for the rigors of the NHL in the here and now.
If Helleson is the real deal (even if his ceiling is a 4/5), it makes what was already a strong future D corps that much better. I'll admit, I thought he was buried in our deep system and was going to have to leave to find a gig, but clearly they saw enough to give him the call up. And he's taken the ball and run with it.
Zellweger, OTOH, I fully expected this out of him. Yes, he's small, but his base is really strong so he plays bigger than his measurements, and his vision/IQ/processing speed is high level. It's not just the offense ... his general reads, zone exits, puck retrievals, stick work, transition D, etc. are all pretty good for the type of player he is, he's not one of those one-way guys who gets his points by taking ridiculous gambles nonstop like an Ozolinsh.