No. You want them all at 1x. That way your CPU has more lanes available for more cards.
Why does it have more lanes? Can i plug more riser cable at a same slot?
No that is not what he meant. He meant that each slot on the mother board is connected to CPU. CPU have limited number of slots you can connect to them.
Basically, answer to your question is NO and extra comment given by him does not really concern you.