Since they're all in flower, one is already thickening up and the smell is getting strong right now.
Grassy and sweet.
Nice.
The other once will still stretch a bit more I guess, so they're getting some more nitrogen for the moment.
You are right in the window
Get the trichome microscope out and check trichomes.. pistils have nithing to do with rippening. Certain strain will have lots if white hair left at harvest sone strain will have hair falling off and that is just genetic. I can have have all hairs turn black in less then 24h 4 weeks into flowering . Hairs can help figurout the harvest window but all strains are unique.