Try teriyaki instead of soy.
It seems less salty to me.
Great idea! Also I am a butter person, so I will cheat with melted butter sometimes. This works because I usually don't marinade the steaks a long time or in the fridge.
Olive oil is great with Mr. Pay's marinade, but I've gotten annoyed more than once at pricey restaurants (I believe they were located in CA) that brought the bread out then plopped down a bottle of oil with a little crushed up spices on a plate to rub the bread in. I was thinking, how much discount do I get because you don't have any butter????