The Fi 156 will be quickly suppressed by even light anti-air but should survive if pulled early enough and then consequently kept out of range. Dedicated anti-air units, such as e.g. M16 MGMC and M15 CGMC or Flakvierling will destroy it pretty quickly though! As a slow flying air unit the Fi 156 are heavily vulnerable to dogfighters.
Use immediately at the beginning to reconnoiter what the enemy throws at you while hoping the opponent doesn't have enough points left to call in a dogfighter. A flying reconnaisance uni can regularly provide information, which ground-based reconnaisance units are not in the position to do.
Use to lure enemy dogfighters into own anti-air defense.
Sacrifice so that the oponent's dogfighters cannot be called in to harm your bombers.
