I can't remember which arch (I think MIPS) or the specific instructions, but there was something about inconsistent arrangement for a couple of opcodes where the corresponding instructions in assembly looked consistent. I think glossing over that is some level above writing pure opcodes.

From what I recall, a lot of assemblers give you convenience macros/pseudo-instructions, which assemble into several machine instructions.

I think, however, it's such a small level above machine code that making a big fuss over the distinction is perhaps pedantic.