Even if there were no errors in this spreadsheet, it's my guess that it assumes a given number of drops is equal to 1 mL no matter what EO you're using. I'd also guess the maker assumed that 1 mL of any EO is also equal to 1 gram.
It's reasonably correct to assume about 20 drops of WATER is about 1 milliliter of volume. For water, that milliliter will weigh about 1 gram. But that doesn't hold true for other fluids.
Someone did a correlation of drops to milliliters for a long list of EOs. Turns out the range of drops per mL ranges from 25 to 52 drops depending on the EO. Since an EO can be quite a bit more dense or quite a bit less dense than water, you can't assume 1 mL of EO will equal 1 gram.
When I convert an EO blend from drops to grams, I use a scale that reads to 0.01 gram accuracy or better. I make the blend per the "dropwise" recipe and record how much that number of drops weighs for each EO. While it would be nice to use a spreadsheet instead, I think this method gives more accurate results.
Or you could use the same scale, count out enough drops of a given EO to equal 1 gram, and then you'd have a reasonable way to mathematically convert drops to grams for that EO.