3 horse finish

My family has preserved three photos that chime with David's "Winning a Race at Happy Valley". Ours are from 1922 which is a later era. I've had some trouble sorting out which ponies were involved in which races, but the race reports helpfully tell you by how much distance the 1st, 2nd and 3rd ponies were apart from each other at the winning post. So here we have Dr F.H. Kew's outsider pony, Wombat winning by a head from the favourite, Mr A.G. Stephens's Hatton, with a neck between the 2nd and 3rd ponies. My grandfather's pony, Mosaic Tile was in 3rd place. His house, The Towers, after which he took his racing name, Mr Towers, can be seen in the upper right hand corner of the photo. The hill behind seems to have a strangely flat top. Can anyone explain that to me? Is that the shadow of the grandstand in the foreground? David mentions the lack of spectators in his photo. Here, the spectators seem to be more interested in what is going on in the background than the race in progress. They are all wearing white, which is different to one of our other photos, where there is a large crowd of Chinese spectators. I'm speculating that the number of spectators very much depends on how much money was riding on each particular race. The race reports are in the Hong Kong Daily Press of 16 October 1922 p. 3 and HK Telegraph of the same date p. 6. Sorry I don't know how to give you the link to those.

There will probably be a time gap while I work out the names of the ponies and the precise event shown in the other photos.