Fictional lore:
Zi. 16 was new evolution of multi-engine planes made by Ziegler. Purpose of this plane was to make high altitude attacker which could absorb some damage and attack enemy armored troops by rockets and cannons. Luftwaffe had prototype for testing in 1941, however there were problems with those engines becase there were no companies able to produce enough amount of engines with 3K horsepower each. Even with those engines the plane wasnt fast enough to avoid enemy fighters. Another handicap was lack of space for bombs and no space for guns around nose. Model was refused by OKL, some of already constructed planes were sent to Romania and Slovakia. No evidence about using them in battle