I shoot high moorland , full of contours that catch the unwary regards wind patterns ! I i was shooting on lower flatter land ? I would tahe my .223 . Mark Ripley is a good shooter but he does seem to shoot a lot of lower, slower and flatter ground . Remember he also has sponsership / tie up's to various . When out on rolling high ground he seemingly favours .260 rem which i myself use as my main deer rifle
I do have .22 hornet and .223 rem and just got my self a 8" twist .243 for sending 80 grain Copper tTSX, heck its far and away the most versatile thing , so i guess i cannot be biased eh? The .223 i use mainly for pests and small pests Rabbits to CWD / Muntjac I have one and use it a lot but i doubt i will go after deer or longer range than say 150 yds with copper .
Now if i was shooting in an area where vehicle and traffic are zooming past the other side of a fence etc i note The man in question that you mention .seems to mitigate danger by gaining height .
If your shooting more open , Lower risk land and habitation though your seriously limiting yourself regards versatility as regards range and wind and the majority of uk deer