Important comparison
On the Moon we see 20-25, even maybe 30 degrees. On Mars, it's 10 degrees, maybe 15 or 18.
There are different processes on the two planets, and, of course, different slopes at different length scales (That .pdf PowerPoint I referenced had some interesting stuff on this).
You have to compare planets and Moons carefully. In theory, you should divide relief or slope by gravity, or something like it. No great surprise that the Moon (1/6 G) is about twice the slope, of Mars (1/3 G)