They've played less than 30 games. You wouldn't count the Giants in the data since they haven't played the next week. However, I wouldn't expect someone dumb enough to believe in this theory to take that detail into consideration.
Oh boy. Your lack of reading comprehension and arithmetic ability are on full display here. Without these fundamental skills, it is difficult for a person to make sense of the world. I feel sorry for the difficulties that day to day living must present to you, and now understand why you find much of what I say untenable: You understand neither the premises nor the logic.
With Houston's fresh loss, the total W/L record for former Dallas opponents now stands at 19-27, or 46 total individual games. That there is some overlap does not matter for the purposes of this sort of analysis (ie, within those W/L Seattle has played St Louis). If I subtract all games actually played against the Cowboys, this still leaves 18-21. 39 games. If I subtract the literal next weeks games, that includes 1 win and 4 losses, so 17-17. An even .500. If we subtract St Louis/Seattle (already subtracted from Seattle as a post Cowboys game) and SF/Seattle just for the sake of argument (overlapping games), we subtract 2 wins and 1 loss, which leaves us at 15-16. 15+16=31. And no, I had no way to include a Giants game which hasn't occurred yet into W/L calculations. So even if I managed to have an error in there somewhere, you cannot claim neither failure to pay attention to detail nor including the Giants game, and we are still 2 games clear of "not even 30 games".
Maybe I need to put in big bold letters that I do not believe this theory. I merely hold that it is a possibility. Reminds me of an atheist calling an agnostic a theist.
I want to be clear I'm not even arguing about the theory itself. I'm merely pointing out your flawed argument. That you cannot differentiate between a bad argument and an incorrect conclusion is another problem. You could be right in your certainty that physicality of play in one week has no impact on the performance of a team in another week, but we have no way to be certain of that based on your argument.