I kind of disagree with this bowling breakdown because 1st day in test our fast bowlers probably won't have to bowl no more than 20 overs (120 balls) and 2nd day most likely going to rest possibly 3rd as well then come back to bowl another 20 overs in the last few days so I don't understand how they will easily break down especially when we can rotate our fast bowlers.
In the 1st test against Sri Lanka, probably be using 2 fast bowlers but if i.e. Rubel and Mashrafe are used in the 1st test then 2nd test rotate one of them drop Mashrafe and bring in Abul then when the ODI starts give i.e. Rubel a rest day and bring in Shafiul etc etc. The best way to go about it at the moment so there are less risks with our pace bowlers.
Nazmul Hossain should only be used for ODIs because of his injuries and lack of pace where in Test Cricket, will be difficult for him to get wickets bowling around 70-77 mph. Rubel has the pace but is not consistent enough in hitting the seam and bowls too wide and short which won't help. In swinging conditions, then obviously Shafiul Islam must be picked and used but he needs to gain a bit of muscle which will make a bit of difference. Ideally I would like to see Mashrafe coming back to the test side but he may have to bowl short spells of 5 overs, maximum of 20 per innings which can be manageable.
If Bangladesh want to be come a top Cricket team, the answer is simple mix your Cricket pitches, make some grounds especially training grounds very fast and bouncy, take your first class structure seriously, play abroad especially 4 day and A games, focus on setting up proper fast bowling programs and so on then we wouldn't struggle especially Test Cricket as much.