I disagree completely (one of the few times with you, dude ). Glenn McGrath certainly has the ability to just knock someone over if need be (and I don't say that about Hadlee because I didn't see enough of his bowling). His ball to Brian Lara in the 1999 WC, then Tendulkar later in the tournament as well as a few of the deliveries he bowled to Lara in the 1995 away Test tour etc. I could rattle off quite a few examples where Glenn has just knocked someone over when need be.Guys like McGrath and Hadlee are on the next peg in that they were good at what they could do - line and length and accuracy but couldn't blast batsmen out.
And having seen Curtly bowl quite a bit, I'd have to say he was a similar type of bowler to McGrath in that he bowled within himself and bowled immaculate line-and-length with a little each-way movement. He didn't really bowl the unplayables as much as a Waqar or Wasim but he was a fine bowler and considering how recently he retired, he's been vastly underrated by Wisden and most people in the 'Best Of' lists.
In my opinion, disregarding his record, Glenn can compared favourably with the WI pacemen just on raw ability. But that's just me.