Do-17 was a nonentity. Even in the BOB it was obsolete and ready for retirement. It had a small minority of bombers in the LW attacks on the UK, but it still sustained a higher loss ratio than any of the other types.
It was the weakest of the pre-war bombers and saw almost no real war-time service. It has little use in the AH planeset other than "just because".
DB3 was about as useless. Also an early 1930s design. The Soviets used it a little longer than the Germans because they had this protective delusion that they wouldn't need newer craft (the German invasion removed them of that notion). FYI the DB3 is also called the IL4. Different companies but the same plane with minor changes, or some such.
For the Soviets the issue is they really didn't have a level bomber fleet. They had tactical air support. They had Pe-2s, but these are lightly armed by AH standards. They had LaGG-3s and such with rockets or IL-2s with bombs and guns.
The Tu-2 would be a good performer but was generally a late-war bomber and not very useful in planesets or scenarios and setups. Nice, yes, but filling only a tiny hole. I say the VVS planeset really needs a Pe-2 but that this is the only real "bomber" it desperately needs. All other VVS planeset holes would be fighters.
P.S. Pe-8 has no real place in this game. It was rarely used, they had all of low-teens digits in service, and were used as long range VIP transports in most notable instances. It simply wasn't needed. It was a morale boosting tool for the Soviet populace, not a real bomber. Flew most of its missions at night, too (I think).
