Not sure what else to call it, but I was wondering what is possible to do in terms of always kinging your cub at the oldest age?

Like, what would the cut off be for kinging my own cub that I personally bred if I want to consistently do it ?

So hard for me to word it..

King 1 - starts at 3y/o
King 2 - can theoretically be the first born cub to the fresh king (so king 1 would be 3y 3m w/o ibf, and cub would be 0m) So this king would be kinged when King 1 hits 16y, so 12y9m ? which would age him down to 8
So now we've got
King 2 - 8 years old
King 3 - born asap, 0m when king 2 is 8y3m. Meaning he would be kinged at age 7y9m? am I correct?

King 3 - 7y9m
King 4 - born when k3 is 8y, kinged at 8y

so would it then just jump back and forth between kings being 7y9m when kinged and 8y when kinged? Assuming I always kinged the first born cub and bred on the first day of kinging