My killer could have been chopped at 8 weeks but I preferred it after 9 weeks.
I also had an MK Ultra that could have been chopped at 8 weeks, it was very done by 9 weeks, it had like 90-95% brown pistils by 9 weeks

Honestly mate theres loads n loads out there its just about finding the right pheno within the strain.
I doubt you would every get a pack of seeds and they'll all finish at the same time.