First of all, you need a player who is in playing 11 on merit. There are only three players who can be in any format on merit, Amir/Babar/Hasan...Amir and Hasan are premium fast bowlers, who need rest and should be rotated with other bowlers on lesser tours and matches, three formats is too much for fast bowlers to play constantly...Babar is only player who is sure start in LOIs, in test he has yet to cement his place...
On the same token, place of Sarfraz in LOI is not cemented yet, only reason he plays LOIs because we don't have better Captain. As a player he is not good enough to be in LOI team, same is the case with Immad...This will be a problem in long run, because when we start loosing because of seniors(well which we already do, including Sarfraz), he will make compromise selection, we kind of already do, Hafeez/Shezad/Malik/Immad/Sarfraz, we cannot play with all of these players in playing 11 of LOI...Team that has this many compromises cannot win on consistent basis...We won CT because our bowlers clamp down opposition for less than 230, four times in a row, we should not assume that as a norm and keep carrying these passengers...There has to be merit and standard in batting...
Secondly, we don't need Captain for three format...T20 Captain should be a young guy, trained for ODI and Test. Babar fits that role, he should named Captain of T20 in 6 month to an year, Sarfraz is not suited for T20 anyway...