Your combat example from 5e may be flawed as if I recall correctly (don't have the rulebook at hand & haven't played 5e in forever) you are allowed to move, attack and move again. So the fighter would be able to move the 15 ft to attack the orgre if that didn't exceed your total movement rate for the round.
Your combat example from 5e may be flawed as if I recall correctly (don't have the rulebook at hand & haven't played 5e in forever) you are allowed to move, attack and move again. So the fighter would be able to move the 15 ft to attack the orgre if that didn't exceed your total movement rate for the round.