West Indies
Kraigg Brathwaite
TBC
Nkrumah Bonner
Roston Chase
Jermaine Blackwood
Kyle Mayers
Jason Holder
Josh Da Silva
Rahkeem Cornwall
Kemar Roach
Shannon Gabriel
Reserves:
Shai Hope
Nicholas Pooran
Shane Dowrich
Keemo Paul
Alzarri Joseph
Jomel Warrican
I've no idea about opening batsmen, so I'd probably go with a bit of a rogue pick. Shai Hope or Nicholas Pooran, or maybe Tagenarine Chanderpaul for sheer optimism.
Bangladesh
Tamim Iqbal
Anamul Haque
Mominul Haque
Mushfiqur Rahim
Shakib Al Hasan
Liton Das
Mohammad Saifuddin
Mehidy Hasan
Taijul Islam or Abu Hider
Mustafizur Rahman
Abu Hider
Reserves:
Nazmul Islam
Towhid Hridoy
Mosaddek Hossain
Aminul Islam
Nayeem Hasan
idk... maybe Taskin?
No Brooks or Bravo in your squad I see. The one main spinner is something I agree with, and Cornwall can bat on his day. For all the good that Warrican did in this series, he'll have to sit out a few games. His time will come again. In that squad you named I think Chase is batting too high and Mayers too low. Probably swap their positions. Roach and Gabriel are practically written down even before you think about it. Still would like to see Gabriel work just a little harder on his no-ball problems, I think they came back to haunt him in the second innings. Pooran's chance in Test cricket is coming sooner rather than later but at the moment I'd slot him into the limited overs team. Joseph sitting out...well it depends on the conditions really. He can be a straight swap for Cornwall if you expect the seamers to thrive. Tage Chanderpaul needs exposure to international cricket but he isn't that far away from that.
Let's throw a random thought out there. Evin Lewis as a Test opener? He's young, talented, and would pretty much fill a Chris Gayle sort of mould to Brathwaite's more defensive style.
As for Bangladesh, got to have Tamim, Mominul, Shakib. Mushfiqur...I'm on the fence. I dunno. A good fifty in the second innings but...eh, he plays. Mehidy plays. You put Taskin in the reserves, there's a player I'd like to see more of. What about Mahmadullah? He must be getting up there in terms of years but I don't think he's out of an international career yet. Good batting, occasional spin, excellent fielder. Liton Das has done a decent job, he plays. Got to have at least two left arm orthodox players, Taijul plays.
On paper, both teams have match-winners. In real life somehow it doesn't always translate.