Cloning from Harvest Plants vs. cloning from a Mother

I have a question about the differences between taking clones from the plants you intend to flower (and harvest) and taking clones from a mother plant that sits in veg for a long time. What are the drawbacks to the first method? It seems slightly more efficient than maintaining a large mother plant in it's own veg space, and it also seems that each successive clones would age on the same timeline as the clones taken from a mother (same timeline as the mother).

The difference is: you don't know what you're going to get. A mother plant will supply you with many clones that are all identical. Here's the proper scenario: take 2 clones from each of the plants that you want to flower. Flower the big plants and save the clones. When the flowers come and the bud is done, you keep the clones from the very best plant and throw all of the others away. Now you've found the best phenotype and you Mother that shit out of it. Take your clones from her, and you'll have a room full of the best plants available.

Doing it the other way sucks for a couple reasons. You would have to cut branches off the plants you're about to flower. You would have no consistancy becuase you'll be using multiple mothers. Also, the timing sucks. If you take clones from plants you're about to flower, you'll have to veg them for 8-10 weeks before the flower room is open again. If you have a seperate mother, you can take the clones whenever you want to and veg them appropriately.