Idle bombers will drop bombs at enemy units, since bombers have large aoe and are normally in bases this is bound to to lead to sever friendly fire. There is no clear way to even make them not do this as a player as there is no 'hold fire' option for them. Setting them to hold fire if such an option exists would be needless micro imo.
#Make bombers not auto-attack by default
rough cairn
pseudo portal
honestly I wish there were a way to give default unit behavior to each individual unit
having bombers set to hold fire while fighters were on fire at will would be nice, I run into the same thing with catapults and kargs for example
urban mesa
pseudo portal
neat!
stoic lynx
Thanks, didn't know that existed and was in by default, just turned it on and used it to change some default settings