I agree, though the terminology has changed at some point during development before release. If you click the Help page for any of the landing challenges you can see four different scoring criteria clearly explained, even though there are only three at present:
- Landing Precision - touchdown point along the length of the runway
- Centre Line - maximum deviation from the centre line during the entire landing roll
- Ground Roll - braking distance from touchdown to stopping point
- Landing Smoothness - vertical speed on landing
In reality, the “Centre Line” measure has been renamed to “Ground Roll” and the original “Ground Roll” measure has been removed. So we have:
- Landing Precision - touchdown point along the length of the runway
- Ground Roll - maximum deviation from the centre line during the entire landing
- Landing Smoothness - vertical speed on landing
I reported the incorrect help page to Zendesk a while back but haven’t checked the help page in the recent update to see if it has been fixed. But in spite of the different naming I think it helps to clarify the scoring measures.
I can confirm that as I test I did some very long roll-outs on some challenges and still got a good score on “ground roll” provided I stayed on the centre line, even when I used up most of the runway 