```python
def pace_of(seconds: int, kilometres: int) -> int:
    if kilometres <= 0:
        raise ValueError("Distance must be greater than zero.")
    return seconds // kilometres

def pace_list(legs: list) -> list:
    if not legs:
        return []
    
    result = []
    for leg in legs:
        if leg['distance'] <= 0:
            raise ValueError("Distance must be greater than zero.")
        result.append(pace_of(leg['seconds'], leg['distance']))
    return result
```