Yes, with the SLog flavors; the way you expose for SLog2 on one camera should be the same on another.
In practice, though, SLog2 on the A7sII or RX100 is slightly different than, say, the FS7, because one shoots 8-bit and one shoots 10-bit footage. So you may see banding in A7sII footage where the FS7 footage would be clean. Exposure-wise, though, it would work the same way.
Don’t make the mistake, though, of assuming the numbered Picture Profiles on the A7sII and RX100 work the same from camera to camera. PP1 might be, for example, “Cine” mode on one camera and “Vivid” on the next. And even the look of “Cine” mode might be totally different from one camera to the other. The only time you should assume they’re the same is when they’re specifically spelled out as a certain color space, like SLog2.