wood clones are the hardest to see through, but strongest is between wood, clay and narutos shadow clones. narutos shadow clones would probably win, they saved the whole war up until madara. madaras susannoo armored wood clones are also very good. i guess the strongest would be between wood and clay and sand, but anyone with the right technique and power like kurama jinks or uchihas with susanoo or kamui, can beat most ninjas with a single clone no matter the type. i left zestu clone out because they are different, zetsu clones are a litteral cone with their own lives, all the other clones are just temporary copies of the user to do certain tasks. so i think we should leave zetsu clones out of it.