That item placement sure sounds questionable. MH and RA right near each other? The Quad and Invis thing is probably the author attempting to create a "teamed" powerup, where either Quad or invisibility spawns, at random, each time a powerup spawns, rather than both. The author can make this work by giving both items a "team" key and an arbitrary string as value, with the same value used on both items. That, and rearranging the armor and MH to spread them all out more, would be a good thing to do before repackaging the map to include the missing textures. :)