Looking at total 2019 matches ie. adding in other levels and qualifiers, Dan has many more matches, particularly vs opponents ranked outside the top 100, due to his own early year lower ranking, and an extremely good record vs such opponents ( as against Kyle and Cam's 50/50 records ). Here, he and Cam also have a bit more noticeable better record vs top 50 opponents than Kyle. Thus overall Kyle is short of 2019 matches and more particularly wins ( less than 50% overall ). It looks fir Kyle more an overall 2019 issue than his relative ( to the other Brits ) Slams & Masters record and an overall record that has caused his rankings fall.
I hadnt realised dan had played 81 matches this year, that's a lot of tennis and travelling. No wonder his end of season has looked tired, as well as not feeling well