I mean it is all opinion, so you can really say whatever you want. You can put Drake as the GOAT if you want, it's just opinion. But there is a strong consensus that Face is top 5 of all time. Rarely will you see that many people put Snoop in top 5.
Snoop was dope in his prime, but his prime was short. He put out straight trash albums after Blue Carpet Treatment, and some of his work in the 2000's was just aite. Face got dope records in the 80's, 90, 2000's and 2010's. shyt he dropped AOTY for me last year with Deeply Rooted.
And one reason why a lot of people will overlook Face is because he never got the mainstream success like Nas, Jay-Z, Pac and Cube got. Face never sold out like pretty much every artist has at one point in their career. There is a reason why kids always talk about Nas, Jigga and Pac. They was on the radio in their primes. Face got no radio play outside of Texas in his prime years. But that's also why Face ain't eatin like how Nas and them are. If face wanted to go the mainstream route, I think most everyone would have him in their top 5. But that's why I love Face, he never sold out and went the mainstream route.