Injury records are still quite often based on the players we or any team have. I believe some of our key players are more reliable. If we relied on Partey, ESR and Tomi to carry us through the bulk of our games, that would be a disaster. We have actually done that in the not too distant past with key players. Most of those players you named are fairly reliable (so far) although the Saliba injury obviously affected us last year. I don't think Rice had a significant injury before he joined us this year.
Having said that we lost Timber to an ACL injury. He was looking like our best summer transfer before that happened. Glad to hear he will be coming back to training soon! I think Partey has played a handful of games. I take your point about luck but the players you rely on game in game out are also part of the equation.
This is also part of Man City's dilemma I feel. They definitely look better with KvB but he has not always stayed healthy in recent years and if he goes down again, I feel City might be vulnerable. But would that be bad luck on City or should they have foreseen this possibility?