Strange eating pattern

I have three CaliKing six month olds that I got from the same person,
who fed live one week and f/t the next,  in rotation.

I feed only f/t.

These three snakes without fail eat....every other week.    They look
and are healthy.

Will this stunt their growth and do you think this is 'okay' for them
developmentally and nutritionally?   It's just an academic question I'm
very curious about as this is their regimen whether I like it or not.