> R600s [...] should include everything from the HD 2400Pro to the 3870.

Wouldn't this be HD 2350 to HD 4290?

> R700s [...] with the HD 4450 to 4890

Wouldn't this start from HD 4350?

> Then there are the cards from the HD 5450 to 6970.

R800 is from HD 5450 to HD 5970, HD 6750 to HD 6770, HD 7350, HD 8350, R5 210 to R5 220.
R900 is from HD 6450 to HD 6990 (except HD 6750 to HD 6770, see above), HD 7450 to HD 7670, HD 8400, R5 220 to R5 310.

> When we get to the R7, R9, and RX cards, we will have a base of earlier cards
> that will be fully supported

GCN-based cards numbered lower than R7 are from HD 7730 to HD 7990, HD 8570 to HD 8970, R5 240 to R5 435.