Red Green wrote:
Be it Sears, HF, HD, etc.

They often go 6,7,8,10,11,12...

Not always in larger sets. But like who would buy an SAE set of any size if
it ran from say 3/8 to 3/4 without a 9/16?

I had to check my set from Canadian Tire (Mastercraft)

4mm - 13mm in 1/4" socket wrench
10mm, 12mm - 19mm in 1/2" socket wrench