Shatanand depicts the Shrimad Bhagwat as a tree, of which the trunk (clearly most important) is the fifth and tenth Skandas. Indeed the Bhagwat is here compared as the Kalpavruksha - the legendary tree that is said to fulfil all the desires of those who chose to shelter beneath it.
The two Skandas are best for understanding Krishna Mahatmya. Mahatma is defined as that which is Atma Swaroop or the best of all. It’s nature or glory is thus defined as Mahatmya. He who is beyond Akshar (divine abode of God), the regulator of time and Maya, who is unique and divine, the best amongst all - Purushottam, the Supreme and who is powerful enough to free all from the bondages of Karma (action), such Mahatmya should be sought from Shrimad Bhagwat, as it is the best amongst Shastras - Sakalsachastramukhyau. One is able to obtain such supreme knowledge from the two Skandas effortlessly.
In the tenth Skanda, upliftment of man and freedom from the bondages of Karma is explained. In the fifth Skanda we learn about the many ways of devotion to God. Devotion to Shree Krishna is extolled by Shatanand even though it is not succinctly stated in the Fifth Skanda.