While I "know" there's no such thing as FT defense, I had a similar observation. In buzzermanager the FT% of the Opponents is calculated. And I was surprised at the range and spread I still found after 9 games in my league.
With a range from 58.1% to 73% and a Mean of 65.27 (SD=4.06). I find the SD to be quite high for a something that should be about equal across teams.
I checked for a difference based on Big 8 versus Great 8 based teams and noticed it was 66.8% versus 63.7%. But this difference was not significant (p=.13). (maybe it was significant before the crossover games)
So uhhhhh....yeah just surprised by the spread, but maybe it will even out more when the cross-over games are done and all teams will have played eachother once.
Crunchy! If you eat fast enough