This is probably pretty accurate.
I have never coached 6 or 8 man FB but I have seen it and I know some coaches that coach it, you are basically just begging every boy in the school to come out for the team. You can only do so much at practice because most of the time you don't have enough players to really scrimmage, so you do a lot of half-line stuff.
Plus, for the most part, you are not having a depth chart, so it is not like there is the "second string center" there is just, the 9th best player.
So your center might get dinged up and more than likely, a dude that is currently on the field is just moving over to center and the 9th best kid is coming off the tiny little wooden bench to take the spot he vacated.
I did coach C-1 and C-2 for a few years and let me tell you, it was very basic. There is nothing wrong with that, we won a lot of games being basic. But our "skill" guys were not getting some amazing coaching or technique work.