Drop rate adjustment will never fix it if you can get duplicates. People are already saying how commanders they paid for are dropping for them.
There is not just money, there is also time and effort
Beforehand if you wanted to get Bulletins that benefited, say T34s, you had to play and use T-34s. It could be a grind, but you knew what you had to do and could go about doing it and could work out roughly how long it would take.
Now this is entirely at random so you have no control at all
And worse, because the system will randomly drop things you already have, you are actually being penalised for your work under the old system