Hi Elzee,
You are right that the Church teaches that the Eucharist (in any valid form – i.e. “under both kinds” or “both species”) is the Body, Blood, Soul, and Divinity.
At the consecration the bread is changed into Christ’s body and the wine into Christ’s blood. An article of faith is that we receive the WHOLE Christ, now living, glorified. Since He is alive and can die no more, His Body is never sperated from His Blood, or vice versa. Furthermore, since He is alive and posses a human nature, His Soul is also inseperable from his Body and Blood. Furthermore, since He also posesses a Divine Nature, which is united to His human nature by the hypostatic union, His Divine Nature is also present with the Body, Blood, and Soul.
The Soul and Divinity of Christ are present through *concomitance – *a “natural connection”.
It is right and fitting that the Body and Blood of Christ are cosecrated seperately – even though The bread changes into the substance of the Body and Blood (and the Soul and Divinity is concomitant with that substance) and the Blood changes into the substance of the Blood and Body (and the Soul and Divinity of Our Lord are concomitant with that substance). This is a sacramental sign for us – where the matter of the sacrament – bread, wine – conform to the reality: Body, Blood.
Furthermore, the SEPERATE consecrations of the bread and wine, sacramentally represent the seperation of Christ’s Body from His Blood at Calvary.
I hope that this helps – this was sort of a quick answer.
God Bless you,
VC