I also think you should have explained how some enemies may generate negative score upon death and initial capture. Any enemies from the Mutant Alliance, the Govt, or civilians will give you negative score initially. Additionally some enemies from some other factions, notably hoes, altar boys and shrine maidens will also give you negative score. Normally a kill is one number, a dead body being looted is another, and capture is double the kill point value. However when you research any live enemy in the game, that enemy's score value upon being captured is set to I think 10. So it becomes ideal to capture and study the enemies that give negative score as soon as you can so you avoid losing score to them. Additionally you can theoretically put off researching enemies that give you higher scores in order to get double the points from capturing them instead of the set 10 but you'll often end up needing to research them sooner than later due to research trees they might unlock and you can't rob them without researching them.
There isn't exactly a good way to know which enemies give which score values without knowing the sprites but it's something you should definitely keep an eye on.