It seems that striders only have 1 texture for their legs, which means that both the left and right legs of a strider has the same texture (which the other leg is not mirrored).
MC-183091 Strider leg isn't mirrored
MC-189860 Striders use the same part of the texture for both legs
MC-177265 Piglin and Zombified Piglin right arm/leg/loincloth textures are identical to the left ones
MC-189256 Hoglin and zoglin tusks textures are not separate