probably pretty general since i don't know the law.
in the sense that if someone is sentenced to life for stealing a car, even if guilty, as i understand it, they would likely have some legal redress as the punishment would be considered not proportional to the crime.
in this case, if strzok were to pursue some legal remedy, even it was accepted that his actions were sanctionable, i would think he could challenge that he was dismissed against the recommendations of the internal fbi report. perhaps he would also need to show not just that such an action was inconsistent with agency practice, but also that there was prejudicial influence or something of the like? if so, i would think that the constant adversarial tweeting of the president would be material.