I think Jesus was setting an example. Also prayer can be something other than asking. It can be, for example, thanksgiving. It can be praising the Lord. And it can be total communion.
Namaste friends, Prayer is simply a means of availing oneself of sattva karma, by directing the mind to concentrate upon the Divine Being. This is done either by thinking upon God, speaking to God (verbally or mentally) or various rituals of offering gifts to God. But it should be remembered that God is not a being like a king somewhere, reaping the gifts of his kingdom. God is the very Self of all things, all beings, all creatures; the very core of one's own living experience. So if a person's karma leads him or her to pray, that is definitely a good thing. That is auspiscious karma, sattva karma. But it is only an external mode of worship. However, the higher meaning that the word 'prayer' signifies, of which the Yogis and Saints speak of, is the offering of the individual consciousness back to the Lord, from where it has descended via Kundalini prana. That offering of Mahaprana back to God is the process known as Yoga Sadhana. That is the internal form of worship. This brings a gradual unification with God, through practice. Om Namah Sivaya
That's possible. However, there's a slight problem with that interpretation. For a start, this story of JC praying in the garden is a bit mysterious. It says he was alone, and that the disciples had all fallen asleep. So who was there to witness it? That isn't only a problem for the interpretation you propose, but also in more general terms - because there can be only two possibilities, first that it was revealed later on to the writers of the gospels by the Holy Spirit, or JC told them after his return from the dead. Neither one appeals to me very much. But in the context, there are problems with saying he did it only to set an example. It can be just a silent gesture even.
a) I didn't say Jesus was only setting an example. I am sure he was in genuine prayer. But probably not the prayer of asking, but the prayer of presence and communion.
It says he asked for a change of destiny - three times according to Matt. 26. 27-46. - not surprising really.