T20 format requires a balance between the ball and the runs. Afghanistan would not have been at this stage if their batsmen had been able to score a little more. Hazratullah Zazai made only 20 runs off 15 balls and Azmatullah made only 13 runs off 12 balls. These issues are now being blamed for the loss in the match. Not only that, if they could have done better on the bowling side, it would have been possible to prevent this score but they failed there too. They needed 11 runs in the last over which was difficult for the Zimbabwe team but they made that difficult task easy. If the good team cannot play well, then it cannot be said that the bad teams will not do well there. Zimbabwe has been performing well recently due to which they won the match against Pakistan and started their new series fight with a win against Afghanistan.
There should be some balance in the performance. When you mention the term balance it also suits the team batting second or the team chasing the target. They will also make plans according to the target and make a initial take off as well as move through out the match. Little more runs doesn't make any big change in the match result. Maybe something as 160+ runs could pressure the team chasing the target and cause loss of wickets.
Even Afghanistan batting were out of touch but still we have good balance into their performance which allow them to have from 58 for 5 to 144 in 20 over Mohammad Nabi and Karim Janat partnership give them good comeback with their bowlers also create good problems for the Zimbabwe in their chase even match was in control of the Afghanistan, but sadly we have 15th over from Naveen-UL-Haq bowled 6 wide and 1 no ball give good advantage to Zimbabwe, and they were able to secure their first win after 5 years against Afghanistan in this format.
As we have no good scorer from Zimbabwe all gone cheaply but Brian Bennett inning were good enough for having win but again 19th over from Naveen-UL-Haq end all hopes for the visitors to have win in this game.