I don't know what's wrong with Lato at 400 weight. Its either the rounded extra-wide dot or something else, but Lato at its standard weight doesn't seem right.

It's there (the Unity / Rhythm / Balance... example)!

Lato is the sixth one in the showcase.

Oh, I just noticed it. But it's only the title, the rest is Merriweather.

For me the sixth is all Lato -- the blue block that starts with "Unity"