If someone wants to write a thesis to analyze Umar Akmal, it can be done.
The truth is, he came into the team as a dasher. However, Pakistan team was prone to collapses and Umar was way too young to curb his attacking instincts. Usually when team Misbah collapsed, Umar was a part of the procession and it wasn't much like he "hung around" while others collapsed around him. He also usually fell to the ugly "cross batted shots".
At that time, a batting coach might have told him he was "talented enough" to play "his natural game plus take the singles and twos on offer" but the Pakistani batting camp was having way too many collapses for Misbah's team to tolerate him.
It was a pity, because he didn't realize that "aggression" is only valued when a team has a stable middle or lower order. He was pushed lower and lower down because he didn't "put value on his wicket". Finally he became renowned as a "lower order slogger".
In a more stable team, he might have learned that "cricket is not about playing all balls to the leg side" and probably developed his career more.
As good as Buttler? Not likely. Because despite his ability and talent he had a severe limitation which was "ability to think outside the box, or to analyze and read game situations". This limitation was even visible in the current ODI series when even though he was basically given "5 games to book his ticket to the World Cup, he struggled to overcome the same mental approach".
Umar Akmal was initially lost by the system.
But by the time he tried to make a comeback, his deeply ingrained habits of "not being able to cope with the mental pressure of international cricket" were far too established for him to ever be the batsmen fans hoped to be.
I blame the system 30 percent but at the end of the day the same system churned out Babar and others, so 70 percent of the blame goes to person for not realizing their worth.
He is still a good T20 and league player. But that's all he will ever be.
Don't want to write a lot on Umar, but he could never have been as good as Buttler. Perhaps as good as Alec Stewart wk/batsmen.