Raw (BARF) diet vs diet with grain - which is better?

[Bijou's Mama]

We visited our vet clinic yesterday for our two other dogs - a doberman and a pom. There are 3 doctors at the vet, the 1 that we had is the one I dislike. He said we MUST feed grain (for the doberman) but all 3 of my dogs eat raw.
Opinions/experiences about that for frenchies? Is grain a must for our loved ones?
My little girl, Bijou, is 6 months and has eaten raw almost since we brought her home and she loves it. No issues, normal amount of scratching, etc.