Answer:
Based on the given actions of Balboa and the themes they best support, the correct matches are as follows:
1. Balboa trains the war dogs to dismember children. Those in power must be ruthless to gain obedience.
2. Balboa regrets not killing Enciso. Those in power live in fear of rebellion.
3. Balboa allows a chieftain to be beheaded by his dog. Those in power must be ruthless to gain obedience.
4. Balboa climbs the mountain alone. Those in power live in fear of rebellion.
It is important to note that Balboa's actions in the given statements depict a brutal and oppressive exercise of power. The themes associated with the actions highlight the fears and methods of those in power, emphasizing the use of violence, obedience, and control.