That means other people do and get away with it. I've used a floor jack to lift my truck up by the differential to get it high enough to put my jack-stands underneath it. Take it slow and easy if you have never tried it before, and don't forget to chock your front wheels so it won't roll.
I would not want to pick up one side place it on a jack stand then move over to the other side and lift it up hoping the jack stand pivots all the weight on an angle till it gets up to an even amount with out sliding or tipping.