The summary is that Afghanistan without many of their top players were able to defeat Bangladesh, and that too paying away from home. Now they have the two match T20I series. Shoriful Islam played a large part in the win by Bangladesh on 11th July, but the batting collapse from Afghanistan was unexpected. For Afghanistan, their bowling was always a notch higher than their batting capability. And this is one of the reasons why they perform so poorly in test matches. Ibrahim Zadran and Rahmanullah Gurbaz are talented players, but they are too volatile.
I don't know which top players of their team are not played in this series. Rashid, Nabi, and Mujeeb are playing in this series, and I count them as the top players in Afghanistan. I knew Shahzad, who plays as an opener for Afghanistan. I don't know where he is and why he is not playing. Except for him, I don't remember other missing top players from Afghanistan. Their bowling unit is strong enough to fight against a top-class team. Their batting line is not bad as well. They can beat anything on their good day. They have some experienced batters like Nabi and Rashid who playing for Afghanistan for a long time now.
Rashid Khan and Naveen-ul-Haq didn't played the third match, which they lost to Bangladesh. And at this point, Rashid is the dominant player in Afghanistan team (still agreed that he played the first two ODIs and contributed a lot). And Bangladesh was playing with a full-strength squad. Anyway, this is humiliating for Bangladesh. They have been defeated by a team that achieved full member status very recently. And who knows? Maybe ICC is also taking note. Bangladesh has continuously underperformed for the last two decades.
