Six bowlers in a test match is absolute suicide. The worst possible reaction to facing a good attack is to say "well, to hell with picking batsman, we'll just pack the side with bowlers". It's really one of the most daft things I have ever seen argued about cricket, and I can scarcely believe you are serious about it.
Warne isn't a test number 6. He'll, he's barely even a test number 8. If that team was picked, Gilchrist would be coming in at 3 down and the tail would begin with the fourth wicket. Under such circumstances, at 3/200 (by all means a good start) you'd be one wicket away from exposing the tail and collapsing. It's just unbelievably stupid as a strategy.
Australia should pick four bowlers in the Ashes. To begin with, if your four bowlers are in form that is more than enough. The need for a fifth bowler only really becomes apparent when one or more of your bowlers is struggling, as Australia have shown over the last decade or so. Furthermore, Australia will need the batting. I think you're wrong to suggest that Australia's batsmen won't be able to hack the English seamers in home conditions, and I think you'll be surprised if you expect there to be such significant swing throughout the series for one, but regardless if Australia's batsmen do struggle then it is much better to add extra batting depth than to take it away and hope to bowl the opposition out for 200 consistently. Picking five bowlers is fine against Bangladesh, but not against a potent seam attack.
The ideal side right now would be:
MacGill, Clark and Jaques would be the obvious reserves. MacGill should and probably will play in a few games, and he'll come in for Gillespie, one would think. Jaques will play if Langer doesn't (but I think Langer will), and I think he might go okay. He's technically more suspect than Langer, though that might be an illusion created by how ugly he is when he bats, but he's got a lot of talent and will probably get by. The weak spots are obviously Martyn, Clarke and Gillespie.
I know a place where a royal flush
Can never beat a pair