---------------------------built------------------------------
. North American P-82 Twin Mustang 
. Italian P-38. 
. heinkel-he-111z-zwilling. 
. bf-109z-zwilling. 
. Belyayev DB-LK
-------------------------OTHER THINGD
The YFM-1 was a “bomber destroyer.”
-----------------not built----------------------
Fauvel AV28
Twin Dornier Do 335 Pfeil
A model of the Me 609.
What purpose were these made for?
Being a plane guy, there are so many planes DF could add that would make the game more cool. I’m still harping on the B-25 and P61 since I am better at bombing then I am at dog fighting. 
I do however enjoy getting a kill on a fighter when they pounce and I find out they are not very good and probably expect an easy kill over my Stuka. But I learned from Maverick, to put on the brakes and they fly right by, and sometimes fly right by right into my gun sights where my Stuka gun makes quick work of them. 
Basically, making a heavy fighter/medium bomber from light airframes, more lift, more fuel, more guns and more bombs. Exceptions are the He 111Z and YFM-1, first was made as a glider tug for Me 321 (those things are chonky) and second is just a quirky construction,
They should add the HE 111 and B 24 bombers to br 3