  Samarium hexaboride is a candidate for the topological Kondo insulator state,
in which Kondo coherence is predicted to give rise to an insulating gap spanned
by topological surface states. Here we investigate the surface and bulk
electronic properties of magnetically alloyed Sm1-xMxB6 (M=Ce, Eu), using
angle-resolved photoemission spectroscopy (ARPES) and complementary
characterization techniques. Remarkably, topologically nontrivial bulk and
surface band structures are found to persist in highly modified samples with up
to 30% Sm substitution, and to coexist with antiferromagnetism in the case of
Eu doping. The results are interpreted in terms of a hierarchy of energy
scales, in which surface state emergence is linked to the formation of a direct
Kondo gap, while low temperature transport trends depend on the indirect gap.
