For me the proposition that Mchale is better than Garnett is like saying Dominique Wilkins put up better numbers than Larry Bird.
Qualification: I'm not saying that McHale was just a Dominique Wilkins level player - he was much more than that. My point is Mchale is to Garnett what Dominique was to Bird. The separation isn't as great but it's a similar separation in my book.
McHale was unbelievable, probably a top five PF of all time - but if I'm starting a team, I take Garnett every day.
It's like asking do you want Dominique Wilkins or Larry Bird?
Garnett is an engine, like Bird, Magic and Jordan were. McHale is an all time great, top five PF who will play great D and get you sick offensive numbers but he won't change the culture of your team by his presence and he won't make everyone else around him better - sometimes just by sheer force of personality.
Parish / Mchale / Bird / DJ / Ainge
Perkins / Garnett / Pierce / Allen / Rondo
If you could argue that Garnett = Bird, Pierce = Mchale and Ray Allen = DJ or Parish ( as far as impact) and a young Rondo and Perkins vs. Parish and Ainge were a wash ( parish and Rondo with the edges...)
Which of those teams above do you think would have won the most titles if they were put together at the same ages - in other words KG, Pierce and Ray got together younger, as Bird, McHale and Parish did.
I think the KG lead team. KG is the Bird of our current Celtics era. That separates him from McHale to me.