Its really quite simple. He's a general wholost his army, so he's amassing a new one. He cares not a jot fir the other members of the camp. What he cares about is getting revenge on Rick and his group. What I think will happen is that he'll tell his new group that there is a perfect place to move to but they have to fight fir it - the prison.
Personally I don't think he killed those guys in the wood. I think it was the other group they spotted. It showed that whilst the other group were prepared to kill to get what they wanted, Martinez wasn't. The thing is, anyone who stood in the governors way was going to die, but I think that initially only Ramirez had to go, partly because he knew the governors secret and partly out of revenge for deserting him. He then tried to escape the camp , not because he felt it wasn't safe, but because he knew what he would do if he stayed. As I mentioned before, he's insane, but he does still have periods of sanity. He was clearly a good man a some time, but losing his family has sent him over the edge - and he knows it.
What I did find interesting was that when he was in thepit he stood with the child in his arms, whilst Ramirez stood in front of him with a gun. I think he did this to stop Ramirez from gunning him down which I think he would otherwise have done. So he's not quite the protective guardian when his own life is at risk