Every side needs a big hitter down the order, our whole side is filled with guys that don't attempt to smash it from ball one apart from Warner. Even in ODIs that big hitter down the order can be the difference between a win and a loss. Think of how many times Cairns, Oram, Morkel, Flintoff, McCullum have won the match for their side when they needed 40 off 20 balls compared to our success rate with same the equation.
Yeah I think you need a mix of smashers and accumulators. So here's my T20 batting order template:
One of your openers should be a decimator eg. David Warner. James Hopes could do it if the team needs an all-rounder there. As mentioned before by Aussie1st, Dighton would be good in this role or Rob Quiney. Explosive openers are important in chases especially, to keep the teams run rate as high as possible at the start. The other opener should climb into his innings after he's had 5-10 balls to settle in and be able to score pretty big once he's going. Shaun Marsh is probably that guy, although Shane Watson or Brad Haddin could do that job too if we need the team balance.
#3 and #4 should be the guys you are expecting to score big. For me it's Ponting and Symonds (if he ever finds form)/David Hussey. Ponting should do similar to the slower opener and give himself 5-10 balls to settle in. I think Ponting's issue lately has been that he's trying too hard to impose himself on the bowling early. The #4 can afford to change his plans depending on how early he is at the wicket, but he should be a pretty destructive batsman hence D.Hussey/Symonds being nominated. Brad Hodge could do either job well too, but I think he's out of the running at present.
#5 is a bit trickier to label. Your #5 might be in early if there's trouble so he can't be an out and out slogger who can't play with caution. But he must be able to pick up the pace when required. An in-form MEK Hussey would be a great #5. Michael Clarke could also do it, but not as well since he doesn't hit boundaries as well. Both guys can run quickly between the sticks and your #5 should be putting the fieldsmen under pressure. Callum Ferguson is also a candidate here. If you lose 2 quick wickets, it might be better to bring Hussey/Clarke in at #4, just to steady the ship.
#6 has to be your clean up hitter. He's too streaky to bat at #3 or #4, but he's powerful and can pick gaps well in the last 5-10 overs. White has the raw skills, but he can never seem to get it right. Luke Pomersbach could be a dark horse for the #6 spot. Symonds would do the job well too.
#7 and #8 are generally all-rounders who aren't expected to score big, so they should have no problem getting a move on. If Haddin isn't opening, he really has to bat down here and get used to scoring quickly from ball 1. There's really nowhere else to put him. Same with Shane Watson, he had to learn how in the 2007 World Cup when he wasn't really suited to the #7 spot, but he adapted and did pretty well.
OK so what have I got left in my batting order?
1. D.Warner
2. S.Marsh (maybe B.Haddin or Watson if wanting extra bowling)
3. R.Ponting
4. D.Hussey (maybe Symonds)
5. M.Hussey (maybe Clarke/Ferguson)
6. A.Symonds (maybe White/Pomersbach)
7. B.Haddin (maybe Watson if Haddin opens)
8. M.Johnson
One other tactic would be to bring your #7 or #8 up the order if you think they can target a bowler well. Eg. Haddin and Mitch both launch spinners pretty well so you could bring one of them up the order to hit the opposition spinner out of the attack.
My two cents anyway...