You make good points in the time/length of the sample size. However, that still doesn’t clearly define anything more than a smaller sample size.
The findings of a longer sample size could be flawed more than small one. There is no clear or definitive qualifying measure other than being behind the 3 point line. For example both sample sizes of multiple seasons or just a couple seasons include early season or late season shots, wide open shots, hand in the face shots, transition 3s, set 3s, catch-and-shoot 3s, half court buzzer beaters, etc.
That’s a bunch of mumbo jumbo, but I say that to ask does a high sample size tell more than a smaller sample size in terms of recency in this instance?