I was oversimplifying. If sex is only for reproduction, that leaves out a lot of positions.
Well, the Song of Solomon clearly wasn’t written about sex for procreation only. Just saying.
God wants us to have a fantastic, satisfying and loving sexual relationship with our husbands/wives. This glorifies Him, as He created it to be enjoyed.
Also, a woman can get pregnant in other positions besides missionary—that sperm will find that egg on her back, on her stomach, or with one foot in the lamp shade. ;^)