Same awg wire but larger diameter on one?
The AWG only tells you the total cross-sectional area of all the strands (or that of a single strand). The conductor diameter can vary slightly with the number of strands.
The number of strands and the insulation thickness is not part of the AWG designation.
For example, this catalog sheet shows 4 different possibilities for stranded AWG 20 wire (solid is not included):
10/30, 19/32, 26/34, and 41/36.
The finest stranding is 41/36 which is 41 strands of AWG36 wire. Because the strand diameters are rounded to even AWG numbers (and, of course, must be integer number of strands) there are slight differences in the cross-sectional area from the ideal.