But I do know a lot more than your average cat.
I would say that We Were Soldiers and Platoon are looking at vastly different points in the war. Early on the sentiment was much closer to what We Were Soldiers portrayed. However, as the war dragged on and antiwar sentiment grew the soldiers began to slip and things became something kind of like Platoon. Of course Stone took liberties and really took most of the worst stories and lumped them into 1 film making the war look worse than it was, but there was definitely slippage the longer we were in it. The My Lai massacre was a classic example of the soldiers slipping as the war dragged on.
Overall, We Were Soldiers was a better and fairer portrayal of that time period than Platoon was of its respective time period.