I know what both of those bits are, and personally know people who use them, thanks.
The point is, BOTH apply more than a 1:1 pressure ratio = curb. I can find numerous pages on the internet and in books that describe a tom thumb curb bit as a snaffle - Doesn't make it any less false. Just because a bit doesn't look like a western curb, doesn't mean it isn't a type of curb. The very definition of a curb is simple - Applies a pressure ratio of more than 1:1, which both of those bits do.