A quick, unscientific survey:
I picked a T1 (Fordham) and a T4 (Florida Coastal) to see where their faculty got their degrees. This only includes people with information visible on the faculty web site, and it only includes JDs:
Fordham (only looked at full-time, non-purely-clinical faculty):
T14 = 45 profs (16 Harvard, 8 Yale, 6 NYU, 4 Columbia, 3 Chicago, 2 Boalt, 2 Mich, 2 GULC, 1 Penn 1 Stanford)
Fordham = 4 profs
Other non-T14= 7 profs (Syracuse, Iowa, Western New England, Suffolk, UMiami, UFlorida, BU)
FL Coastal
T14 = 8 profs (2 Boalt, 2 Harvard, 1 each Mich, GULC, Penn, NYU)
Florida Coastal = 1 prof
Other non-T14 = 30 profs (7 UFlorida, 2 FSU, 2 Howard, and 1 from lots of places of all rankings)
Also good to note that lots of these people have LLMs from T14s and lots have other degrees as well. Not all, though.