what is the implicit meaning of "It's generally easier to think"?
Solution 1:
The comparison is to other real or imagined alternatives. If you are doing a job and advised "its generally easier to..." the comparison is to what you were doing. In this case the comparison is to what the author expects you might be using as a way of thinking of "them". "Easiest" might also be used in a similar situation, but the author may be concerned it sounds too prescriptive. Using "easier" is a weaker way of making the suggestion.