From your description it seems you have the blocks at the feet of the slope. If it was proven that the cut slope is stable long-term, you would have mainly to prove that the foundation outfit is enough to keep the things safe and reliable. But if this is a new cut, with no akin experience besides, not even the slope stability can be taken from granted. Hence a study of overall slope stability may be also required, because it might fail even down under the foundation of the stopping block foundation, even if competent enough to force the failure elsewhere than at its toe.
If you can think that for sure you will have a toe failure, it is still a case to be considered in the overall slope stability study. Furthermore, the formulas of bearing capacity usually are derived for symmetrical long-wall footings, and the bearing of these walls or blocs is unsymmetrical in that one side has far less overburden than the other.
In all this means that I see more prospective success for analysis in the slope stability hypoyhesis, assuming logarithmic spirals or the locus of maximum shear stresses revealed by 2D plane strain analysis for the soil.
