I think that's right, with often favourable overhead conditions and the Duke ball in England, there is more than enough sideways movement, to not need to be 90mph plus.
On these hard, flat, bouncy Aussie wickets with pretty much no sideways movement, its all about express pace and bounce, we really don't have either and our bowlers are looking very ordinary in the conditions.
Add to that our batsmen are looking often very ill at ease, with their extra pace and bounce and another 5-0 is beckoning, I think only some very poor weather could save us.