I know you guys hate reading instructions but, if you refer to an SK catalog you would see that there are actually
five lengths of 3/8 drive SK chrome deep 6 point sockets. Sizes 6 to 13 mm are 1.75 inches long overall, sizes 14 and 15mm are 1.86 inches long, 16-20mm are 2.5 inches long, 21 and 22 mm are 2.75 inches long, while 23, 24, & 26 mm come in at 2.82 inches long overall.
Now about broach depth, the catalog shows sizes 6-10 broached 0.19 inch, 11 mm 0.22 inch, 12mm 0.24 inch, 13mm 0.27 inch, 14 & 15mm are 0.33 inch, 16 & 17 are 0.38, 18 mm 0.40 inch, 19 mm 0.44 inch, 10mm 1.87 inch, 21 & 22 mm 2.12 inches, 23, 24, & 26 mm are broached 2.18 inches.
Those 3/8 extra deep sockets in sizes 7-15mm are all 2.14 inches in length overall, you can look their broaching up as research practice.