The reason why players like shakib and tamim doesnot have marathon record like virat kohli, steve smith, azhar ali, joe root, moeen ali , is that they didnot getting enough cricket, and this is not good sign for bangalesh cricket fan. The biggest example is that England play 17 tests in 2016, while bangladesh plays only 2 and they even beat england in the little opportunity they got, I am just watching the record of tamim Iqbal in tests as he plays only 44 tests in almost 10 years, while player like cook play 140 in 10 years, even asad shafiq plays 50 tests in 5 years. So in simple tamim and shakib would be world class if they are playing in bigger team.