:nth-type selectors

Given some CSS (in Sass format) like the following – from a real example – should you also use an :nth-of-type selector on the basic rule (.gi) so that it’s only 33% wide if nth-of-type is supported?

@media all and (min-width: $bp-large) {
	> .gi {
		width: 33.3333333%;
		
		&:nth-of-type(2n+1) {
			clear: none;
		}
	
		&:nth-of-type(3n+1) {
			clear: left;
		}
	}
}

If you don’t then the .gi element is 33% all the time. It seems to assume a correlation between media query support and nth-of-type support, which we should be very cautious of making that determination.