I really do not see the comparison. Their length is more a difference than a comparison point---McHale has been reported to have an 8' wingspan, Olynyk's is 6-10. I agree Olynyk has nice touch, but to date he has shown about 1% of McHale's inside touch---Olynyk is much more a jump shooter and mobile guy than a pure post-up scorer.
To date, I'd describe Olynyk as a face-up big man with a jump shot, unusually good mobility, and strong passing skills who has not shown much defensively either outside or in the paint; he is also regularly beaten physically. McHale was a low-post big man with incredible moves (he had his 'pumpkin' turnaround move from his rookie year, and added to it as his career went along), exceptional length, strong defensive skills including both man defense and help d shotblocking who was strong (for his era) and a strong rebounder. McHale became a solid passer but didn't really start that way; he had no jumper at all until late in his career.
Personally, I think Olynyk has some interesting potential but do not think he is much like McHale at this point, or likely to develop the same way....I see very different strengths, builds, and games. If I were going to compare him to a big guy I'd think the good-do is maybe a jr. Tom Gugliotta or (offensively) some Vlade Divac (not the defense or rebounding), with the more likely offensive game as a little better version of John Salley (adding range). And any of those would make me happy...I'm a fan of the skills, though he clearly needs a lot more development
