"The Taill of the Paddok and the Mous" and "Journey to the West"

There is an interesting parallel between Henryson's fable of the "The Paddok and the Mous" to one of the adventures in a Chinese classic titled Journey to the West. In that section, the main characters are the four monks in search of the Holy Scripture of Buddha. There is one master monk, and the other three have been some sort of supernatural creatures prone to mischief, and have been tamed to protect the master monk on this quest. Two of the supernatural creatures are animalistic (a monkey and a pig).

On the way to the holy land, these four get a ride down Heaven River on the back of a giant white turtle. Their trip there is smooth. As payment, the turtle asks the monk to ask Buddha the secret to losing his shell, so he could be human. If I remember correctly, the monks forget to ask Buddha this question. On the way back, the white turtle comes to bear them back. When they are on his back, it is revealed that they have forgotten to ask for him, so the turtle gets angry and shakes them off. Luckily, they survived, but the rolls of scripture were drenched, and the time that it takes to dry them leads them into more trouble.

The paddock and the white turtle seem to be similar conduits in that, no matter the intention of the apparent friendliness, the motivation is always selfish. And it seems that in literature, when the protagonist fully trusts another with life or spiritual salvation, the trust seems to call for questioning. Is this a pessimistic view of the necessity of self-reliance?