Well, because i play through it at Insane difficulty moments ago... this mission is still very good solveable, even it is slighty harder yes, as most of the missions in the last part of the campaign because well.. this game comes to a conclusion.
But the hardest part in this mission is still to get the Bonus objective. So to save all four escape pods, which is a very hard task on Insane, yes. But should not be on lesser difficulties, except you take too long with the two Dragons.
After you get the message from the Pinnacle (or Hope if you saved it in the mission before) that the Shivans are attacking the Terminal, shunt all your energy into the Engine and order every Wingmen to protect the station. So close the distance and intercept the first two Shivan wings. The Escape Pods are save from now (as they were in the original mission)
After that, you will encounter a wing that consists of three Nephilims and three escorting Manticores. (in normal FS these were 2 seperate wings that show up at the same position every time, which was much easier) You have to keep in mind... the Shivans will retreat when the Pinnacle (or Hope) is in position. Also this 6-ship wing will only reappear after you have taken down all six ships. So destroy the Nephilim first and then the Manticores. The longer you need to take down one wing, the less enemies you have to fight.
Especially on Medium upwards, you will likely lose some of your Wingmen during these skirmishes, but in return you will get fire support by the Pinnacle (or Hope) because it is closing the distance to the battle area until it is in position. But if you issue proper orders to your wingmen (attack specific targets for example) you can rise their survivability much more.
Actually it was planned to use two enemy wings of four ships each, but because the escort wing will never show up at the same time and position near the bomber wing after the initial wave, the 6-ship wing was introduced instead. Also due to engine limitations these wings have to be destroyed completely before another six-ship wing can appear, which was also planned differently, because a new wave was intended to appear after the previous one has only one ship left. So actually i planned this mission even harder than it currently is.