After completing my multi-instrument I was preparing to begin training for single-engine commercial. An instrutor strongly suggested I earn my multi-engine commercial and THEN begin work on my single-engine commercial. He said that earning my comm in a twin first would satisfy the requirement for demonstrating manuvers in a complex single during my single comm. So instead of demonstrating comm manuvers in the arrow, I'd just do them in the C172 b/c the seminole took care of the complex requirement. I've had difficulty comfirming/denying this with the regs. Comments and clarification would be appreciated.