That sounds like a weighted graph, with different factors contributing to the weighting. Kills, terrain type, etc. can all play into that to account for each un

That sounds like a weighted graph, with different factors contributing to the weighting. Kills, terrain type, etc. can all play into that to account for each unit type's strenths and weaknesses plus historical factors such as number of kills. If you want to get clever, you could implement kill weighting while taking into account whether or not information about those kills has been communicated through direct observation, message relaying, sound, and so on. If you get really clever, you could end up with enemies who remove evidence of their kills to maintain the element of surprise, who hunt down last survivors to prevent the information from being communicated, and other emergent behavior.