Threat actor properties
When building up a picture of an adversary, it is important to understand what motivates them, what backing they have, and what approaches they may use.
Resources
The resources available to a threat actor can make a big difference to the effectiveness of the attack. Government-sponsored threat actors working in large teams will have lots of available resources, including sophisticated hardware and software tools. They have access to money, time, skilled people, intelligence, and so on. They can deploy personnel physically to perform reconnaissance missions. They can also access intelligence gathered by other government agencies.
Time
Nation-states or organized crime threat actors are full-time professional hackers (it's their job); they are not doing this as a hobby. Another consideration is the amount of time that they have access to your systems for. APTs may be in place for months or years without an organization's knowledge. This means...