With Therion, your path skill lets you steal from random people, and Cyrus lets you inspect people. I haven't noticed that the chances of these abilities get much better with level.
For example, I found a kid with lots of great things to Steal, but they were all 8% or less, but it was pretty much the same for the levels I checked him at. Cyrus seems about the same, where it seems like the "person" dictates the chance of succeeding.
Do the Path skills have a soft cap? What is it based on?