I would agree with that. BG do well on many hard surfaces including larger mixed rock up to golf ball size while SMB can use that size up to softball size or bigger mix.

You can make BG beds. Find a location where there will be 1-4 ft of water covering clay (no silt wash in). Take a shovel and place the back side of the blade on the ground and step on it so it makes a depression like those in the last pic. Put about 20 of those together like pic. Then put a small amount of gravel in the bottom of each depression.