Won't compare Cook with Mushfique for a number of reasons, first of all Cook hasn't captained before in Bangladesh so it isnt completely fair. Secondly while Cook's field placings were questionable at times he did continue attacking with reverse swing in the first match which eventually won him the test match, I can't see any example of Mushfique winning it is with his decisions, also as you mentioned the team strengths are different.
You mentioned incompetent bowlers yield negative captaincy, I agree with that but what I will say is you can't control how bowlers bowl, but as a captain you should control when they bowl. Mushfique throughout his career and especially at crucial stages in the last 2 matches has proved as a captain he is unable to even the simplest of tasks, that is managing the workload and rotation of his bowlers.
And while there are variables to performance of the team Mash has thankfully shown that captaincy and good captaincy changes brings about major changes in the success rate of a team. Mushfique has resigned 3 times, does not even get to captain BPL teams, not trusted anymore in ODI and T20 setup anymore for good reason SHOULD NOT be a captain of the test side.
Taskin Ahmed Tazim : 143 KPH - 18 years - Against Aussies - 1st April, 2014
148 KPH - 20 years - Against Pak At Dhaka - 2nd March 2016
150 KPH - Coming Soon.. Will be the first Bangladeshi