Starter and grower are two different types of food though. You mean mix them together?
Not all brands have a separate starter and grower. You youngest chicks at 7 weeks can certainly switch over to grower, or you can stay with starter for all the birds... as long as you're not feeding layer until the youngest are old enough to lay it's fine however you want to do it.
Flock feed...? What is it called, like at the store? Sorry I’m kind of a newbie!!
"All flock" as implied by name is a feed appropriate for all ages of chickens, also called flock raiser, hatch to hen. It can be nutritionally similar to starter and/or grower.