When steel is being used for structural purposes where environment is not a factor (such as weathering steel, high temperatures, corrosion issues, etc), then generally matching the base metal properties will be acceptable. When things like corrosion/creep, etc come into play, the environment must be know to make a sound decision. For instance, if welding on 316 that is in high temperature service, it could be said that using a dual classified filler metal such as 316/316L will match the base metal. However, even though it meets the AWS spec for 316, it may not have enough carbon to resist creep, and could lead to early failure.