Well i can honesty say that it was a lot easier to do when i first did it
I recorded the last bits of the mission (i wasn't sure how long it was going to take so i didn't record it from the start ) I listened to some music too, hope you don't dislike it
You can use these tricks to make it easier, also imo the guards are the most dangerous enemies, they do so much damage with those rapid firing ptrs Remember to spam the flare because its free and upgrade the top mg asap, because you can't rely on the main gun to do damage at enemy inf
And remember to save the game after every captured point.
I noticed that the mortar hold fire does not work, it will continue firing automatically, also id like to add that the counter barrage could be actually useful if it didn't have a shared cooldown with the normal barrage