There is no question that aerodynamic drag is a factor that Tesla optimizes. Tesla also does a good job reducing rolling resistance and other range reducing inefficiencies.
But I'm not at all sure the article in the OP is correct, as they are simply comparing manufacturer claims. Tesla is known to exaggerate. I'll bet a dollar the differences in real world range (side by side) will be a lot closer than the specs indicate.
Tesla cars don't meet their rated range at real world highway speeds. Just yesterday driving to and from Savannah, an 800 mile round trip, I saw 2 Tesla cars on the side of the road. I "suspect" they ran the battery out.
The EPA measurements are taken from a dyno run vs a mfgr. claim.