The problem for bangladesh is that they never get to play any teams worse than them, other than zimbabwe and west indies b. They really aren't that bad, they would beat most of the associates easily imo and would be favorites against the best ones, they're just not up to the standard of the elite international sides that they mostly play. There still hasn't even been a full generation of cricketers to come through since they started playing tests, so I guess they deserve a little more time. At least they have one international class player now. In any case a second tier with more teams playing regular test and ODI cricket would be excellent for fans of these countries. Yeah I know you would sacrifice the tradition of test cricket a little, but tests are a joke nowadays anyway with the parking lot pitches and amazing bats, it's nothing like the game of old. It has to be demoralizing to be a fan of BD/Zim knowing that the best hope you have is stealing the odd ODI or T20, or not losing by an innings in the test. Regular games against the top associate sides would probably lead to far more competitive and interesting cricket.
I guess I don't know where you draw the line. For example, I think SA, Ind, Aus are clearly a cut above and then SL, Pak, Eng are kind of in the second tier, but WI and NZ commonly win a few games or a test, even a series off the second tier and the second tier would be favorites at home against the first tier. I don't think it's as imbalanced as it looks and I don't think you can just break up these eight teams.
I guess I don't know where you draw the line. For example, I think SA, Ind, Aus are clearly a cut above and then SL, Pak, Eng are kind of in the second tier, but WI and NZ commonly win a few games or a test, even a series off the second tier and the second tier would be favorites at home against the first tier. I don't think it's as imbalanced as it looks and I don't think you can just break up these eight teams.