Joining sleeves for vest, knitting in the round

Hi there. I’m having some trouble reading a pattern for a vest that I am knitting my 2 yr old.

Pattern reads: cast on 120sts, knit until piece measures 9". On the next row, knit until 4sts before the first marker, bind off 8sts. Repeat on other side. Knit until you are at the middle back. Put aside.

Arm edges- cast on 48sts on US4 DNPs. k2p2 for 1". Bind off first 8sts of the next round. Make another and place them onto circular needle with the body piece. You will need an extra needle to keep some of the sts on while you get them on there. Make sure everything lines up right. You want the bind off edges facing each other. Knit back and forth from now on.

My question is, the body piece where it says knit until you are at the middle back. Seems to me, if I put the sleeve on now it would be on the back?. Wouldn’t I knit to the bind off on the body piece then add the sleeve, knit around to other bind off and add other sleeve?

Very confused. Any help would be great! Thanks

I’m not sure why thay want you to pause at the middle back. Clearly from these directions:
“Make sure everything lines up right. You want the bind off edges facing each other.” they want the bound off sts aligned. You have the right idea so go ahead and continue to the armhole and then over the sts of the sleeve as you indicate.

Yeah, I was confused too. Thanks for the reassurance.