I served with 1/5 in 2003 as a Forward Observer. The battle portrayed in video 4 is one of the least known battles of the invasion. 1/5 took over 80 casualties in about 10 hours of fighting. It seems to have been forgotten by most of the history books that have been written lately.
If your interested in learing more about 1/5 and there battle to take Iraq. Check out this following book and video.
A Table in the Presence by Lt. Carey H. Cash. Written by the Chaplain. It's religous but gives great accounts of some of the battles.
You can also read this book. Oliver North traveled with 5th marines during the invasion. He describes some of the battles 1/5 fought in.
The Fight for Baghdad This is a discovery channel documentary. In the last 15 minutes it dedicated to the above battle. You will see several Marines talk about being shot etc...