Why might it have been valuable to Constantine to claim divine aid in his victory over his rival

In celtic mythology, one story involves macha, who was pregnant at the time she outraced the king’s horses on a wager. in norse history, freydis eiriksdottir was pregnant at the time that she single-handedly turned back the natives of vinland, who were at war with the norse. what do you think that pregnancy of these warrior women figured do prominently in mythology and folklore, as well as historical stories?