Jimmae
Brownlow Medallist
I'm suggesting that the players and stewards often don't give enough of a shit.That's a bit of a laugh. Apart from point 3 (fine, take an average over a few days/nights if you really want to), but if you cannot accurately measure height due to points 1 or 2, find a new job.
3 cms here and there isn't going to make or break a player. They'd be more focused on measurement techniques to assess current level of flexibility, or to get the correct shoe fit.