Precisely! This is what I was referring to as the trivial aspect. It is explained fully in the blog post linked below.

"Because splitting up a stream of bytes into instructions to feed into eight different decoders in parallel becomes trivial if every instruction has the same length.

However, on an x86 CPU, the decoders have no clue where the next instruction starts. It has to actually analyze each instruction in order to see how long it is."