Grove connector SMD footprint dimensions
&lt;rant&gt;
Amazing. How some engineers could indeed forget putting half of the critical dimensions here? How can Seeed publish this datasheet as if it was useful?
&lt;/rant&gt;

Anyway... I made some research. It appears this same connector is used on some dev kit of TI called "SimpleLink SensorTag Debugger DevPack" (dunno what it is exactly), which mentions Grove conectors in its marketing material. And the BOM lists the connector part number as 1125R-SMT-4P, which is the part number mentioned in the datasheet you linked and also given by Seeed on its Open Parts Library catalog. So I'm quite confident it is exactly the same.

So I downloaded the design files, loaded the gerber files in some gerber viewer tool, and measured the dimensions on their layout:



It gives: B=3.4mm, C=4mm, D=3.6mm.

Just noticed Hayman updated his answer. He doesn't obtain the same results, but most certainly, both layouts are appropriate. They just don't have the same clearances. Well, maybe you can buy these conectors, measure, and report back.