I don't have the 911 SC spec book handy (because I have yet to cut one apart and scan it) so I only have the '84-'87 Carrera spec book that I scanned.
I do have the '72 to '81 Workshop Manual handy and it has all the cam information for the engines. Here's the SC pages.
You can see the cam part numbers are different between SC & Carrera. But it's been said for a lot of years Carrera and SC cams are the same profile and the only physical difference is how the ends of the cams are fastened. That's sort of true since the specs of both cams are VERY close- note how the opening and closing degree descriptions are nearly the same for each.
But the point of my sharing this is to confirm the TDC overlap lift specs are indeed different for SC vs. Carrera according to the factory documentation. But they're quite close to being the same exact profile. Dougherty just lists one grind for his SC/Carrera cam
Dougherty Racing Cams Porsche 911, 930 and 964 camshaft profiles
But getting back to the factory info, I guess it shouldn't be surprising that the TDC overlap lift specs are different since we're talking about different engines with different displacement, different piston dome volumes and different compression ratios?
Lastly, Web Cam has an interesting page with a lot of info to digest (or ignore) for whoever's curious
Web Cam Racing Cams Inc. / Degreeing