Hi - couldn't find the battle on 'scots romans' until I googled 'caledonians 9th legion', which gave good background. I didn't realise that the losses were so bad that the entire legion had to be reformed from scratch, and that the *replacement* 9th Legion appeared to have been wiped out some time later. 
Also, re Lang Vei, I was looking for accounts that tell the story from the Vietnamese point of view - there's lots of stuff on various heroics by Americans, but nothing about how the battle was planned and executed by the Vietnamese. This would tie in nicely with your Night Combat, because clearly it was an attack designed to use the night as a tactical advantage. And the use of tanks was a fairly radical departure in that context. I'm guessing the US forces must have been aware that tanks were in the area, because there were around 100 LAWs rockets issued to the base, but the preparedness for armoured attack is also not really covered in the article except to say they 'weren't ready' for such an attack. This doesn't make much sense - if they were issued with a huge ile of anti-tank weapons then they *must* have expected such attacks? Again, it would be useful to hear from the Vietnamese on their opponents preparedness or otherwise. Normally of course, the history is written by the victors - but not in this instance! That's probably because all the US vets speak English and use the internet, while the Vietnamese have a language barrier and no AOL.....