The lugs on a concert tom are installed further from the edge of the shells than regular tom lugs.
I think that may be a simple optical illusion due to the difference in lugs... well, for Ludwig anyways (not sure of the Tama, but looks like Ludwig was using the same drilling jig for their toms). See the attached photo.
The camera wasn't 100% perpendicular to the drums so the measurement may seem off visually just a bit. I didn't want to pull the reso head off the other drum to measure the inside, but visually those holes are in the same spot.
Left drum = concert/melodic tom
Right drum = double headed tom