Question about when Shaka sent the whites in to battle

This is a great series, and I have enjoyed it over the years. I have wondered if Shaka had sent the whites into battle thinking they would lose, or did he just want to see what their military tactics were? If you watch carefully during the battle, right when it looks like the whites are going to be overrun and killed, Shaka appears to show true concern for them. It looked like he was about to send in reinforcements to help them, but then they got the upper hand and did not need them anymore. I just thought that was an interesting scene, and have wondered what Shaka's true motivation was in sending them into battle by themselves. He obviously showed concern for them when it looked like they were going to die, so I do not think his intention was to have them killed off. Anyways, this is a great series.