You do not need late order batsmen , if your top order batsmen are rubbish. If we take an example of India or great Australian team, their top 3 or 4 do amazing job in seeing new ball, knows when to accelerate and how to do that. If I recall they hardly have consistent late order hitters. Yuvi played role at #4 or #5 most of the time. MS in his days came at # 5 or #6. And very rarely they won the match because of late order hitting (except that fluke innings from Dinesh Karthik who smacked Soumya Sarkar, poor captaincy from BD).
India had MSD, and Great Australian team had Bevan, and Hussey (later) to play sensibly with tail enders, rather than swinging wildly, and lose games... We truly misinterpreted the definition of lower order batsmen, and wasted our time in looking for power hitters.
In ODIs, You would need late order hitter only 1 in 10 matches. In other 9 matches, either he will come too early, or will be too late and too much for him to do any thing. So, team management should stop wasting spots on likes of Asif Ali as specialist late order batsmen. Hasan Ali, Amir or Wahab could do better job if tasked with 30 runs in 3 overs like situation. I don't expect Asif Ali to do any good in that case.
In T20s, you have to have your top 6 going, and to contribute enough to win the game, rather than saying we have power hitter and will come to save us. In my last 30 + years of cricket watching, only Lance Klusner/ MSD (to some extent) were someone who could be labelled as best late order hitter with huge impact. They knew how to play with the tail enders, and they had power and more importantly brain, and calmness to get the job done. We can not expect that kind of awareness, skills, maturity and calmness from Umar Akmals, Asia Alis's etc. Can we?? They have not grown yet in all these years to a level to get the job done for you. Might hit some fancy boundaries to tell the world they have potential, but that potential of what use if that can not win games for your country.
In summary : We should not focus only on 1 power hitting spot as a matter of big concern, we still have 5 spots in top 6 that are up for grabs for good batsmen. If your top 6 can't do the job for you, then don't expect anything from 7th batsman, that will be pure gamble.