The other ratios have inverted over the last 6 months, I think as early as the 5-1 ratio in January. The 10-2 is simply the more extreme indicator and the bigger signal that a recession will probably happen in the coming 12-24 months. I used 10-2 both as it is in the news this week and is the critical indicator that I studied in college. In January I was referencing the 5-1 as an early indicator that without correction would lead to the 10-2 inverting as well.
You didn't come to the number 10 - 2 independently. It was cherry-picked to fit the narrative.