What does being "hostile" have to do with it? As if that is the only criteria by which an attack could be any good? Anyway, so far as hostility goes, I guess the Windies team from 2003 which contained Tino Best and Jermaine Lawson was fairly "hostile". Donald and Hayward are also quite a "hostile" pair. Variation? Well Australia faced Indian teams relatively recently which had a leg-spinner, an off-spinner, and a left and right arm seamer... that's quite varied. Sri Lanka presented a similar team on occasion as well.
Now, as far as quality goes, which is actually a relevant issue, well Australia has faced quality attacks from Pakistan (Wasim/Waqar/Shoaib/Saqlain, Waqar/Shoaib/Saqlain/Kaneria, which were far better than you seem to think), India, Sri Lanka and South Africa over the last few years. Of course, there haven't been that many great attacks in international cricket of late (not that there are ever many!), but when confronted with good bowlers Australia's batsmen have shown themselves to be more than adequate.
It was inevitable of course than fans of X team, whereupon that team broke Australia's long unbeaten run, would claim that Australia were in fact never any good and just never faced opposition as good as said team X, but really there's no evidence to suggest it. Each of Australia's batsmen (excluding perhaps those newest to the team) had significant past success against good bowlers, including against those significantly better than most in England's current team. And while England's bowling attack is very good and does indeed take strength from being a five man attack with some variety, it is not anywhere near as good as you would have to believe to mark it SO FAR ahead of the attacks Australia has thrashed in the past that Australia would be brought down from being utterly dominant to completely exposed. You will find that it is some remarkably good bowling and some uncharacteristically poor performances from certain Australian batsmen as well as some level of age-related decline that led to Australia making moderate totals in the series, rather than being exposed as overrated hacks by the God-like English attack that puts all others to shame.