From the moment the alien battleship emerged from the gas layers of the brown dwarf star, Neville should have realized that his father's fleet had no chance of defeating this powerful opponent.
Instead of trying to save as much of the fleet as possible, he should have given up on most of his comrades and prioritized the safety of his father.
If his father was transferred to a smaller and less conspicuous starship and rapidly moved away under the escort of the Unrelenting, then the chances of saving his father were much greater.
In fact, if Otrus Magrin was willing to sacrifice everything, then he could have transferred to the cockpit of the Unrelenting and allow the ace mech to warp away from this star system!
The journey to a safer destination would be long and uncomfortable, but at least his father would remain alive and protected by a powerful ace mech.