The Minetown Watch should grudge orc-class monsters, in order to both give them an opportunity to actually do something in some games and to hint at enmities between Minetown and orcs that in some universes led the orcs to pillage Frontier Town and take it over. They should probably not be hostile to the player; it would makes for more consistent flavor if they did, but in practice this would probably make Minetown and the lower Mines inaccessible to early game orc players and would therefore be too mean.