Sorry for the confusion. Now we are talking about fetters:
In MN64, jhanas are mentioned up to the base of nothingness. It does not include the base of neither perception nor non-perception.
In MN120, When we have faith, morality, learning, generosity, and wisdom, we can reach many realms and formless jhanas, but there is no mention about the first 4 jhanas.
To eliminate the corruptions which are the fetters, the key is in the following statement. Without this, we cannot eliminate the fetters even if we are in Jhanas.
“Whatever exists therein of feeling, perception, formations, and consciousness, he sees those states as impermanent, as suffering, as a disease, as a tumour, as a barb, as a calamity, as an affliction, as alien, as disintegrating, as void, as not self. He turns his mind away from those states and directs it towards the deathless element thus: ‘This is the peaceful, this is the sublime, that is, the stilling of all formations, the relinquishing of all attachments, the destruction of craving, dispassion, cessation, Nibbāna.’ If he is steady in that, he attains the destruction of the taints. But if he does not attain the destruction of the taints because of that desire for the Dhamma, that delight in the Dhamma, then with the destruction of the five lower fetters he becomes one due to reappear spontaneously in the Pure Abodes and there attain final Nibbāna without ever returning from that world. This is the path, the way to the abandoning of the five lower fetters.”
We can see that “This is the path, the way to the abandoning of the five lower fetters” is in this “Whatever exists therein of feeling, perception, formations, and consciousness…” section. This section is the path.
In MN120, with faith, morality, learning, generosity, and wisdom, one can reach many realms up to the base of infinite consciousness. If the being wishes to be there then he will be reborn there.
The last part in MN120
“Again, monks, a monk has faith, morality, learning, generosity, and wisdom. He thinks, ‘From the elimination of the corruptions, may I attain and dwell in the incorruptible mental liberation – liberation by wisdom – having personally realized it here and now with higher knowledge!’ He attains and dwells in the incorruptible mental liberation – liberation by wisdom – having personally realized it here and now with higher knowledge. Monks, this monk is not reborn anywhere.”
This liberation here does not require to be in any jhana level even if one can be in one if one wishes since it can reach formless jhana too. However, for liberation, the monk must eliminate the corruptions which are the fetters. To do so, he will need to see the same thing as in MN64 even if he is not in any jhana. Without doing the path above, one will not be able to eliminate corruptions.
If anyone can do so anywhere Jhana or not, he will cut the fetters. I do not see that one must be in Jhana to do so even if Jhanas are the best way to do so.
Some people can be in Jhana, but get intoxicated with it and get stuck in it instead of eliminating the fetters. However, Jhanas are still the best tools to do so.
So I do not see any problem between MN64 and MN120.
That’s how I understand.