In that list of complaints, you forgot the dodgiest Ace in the history of Valkyria! On my first playthrough, I wasted so many CPs killing that piece of shit!
The Ace in this chapter is tough because he's a trooper and you are scouts. There is a big firepower different, even before defence debuff from enemy scouts. But if you attack from grass or from behind, like in this video, at least he won't dodge. Which leaves the matter of surviving his counter attacks which is the hard part. I lured him to reposition where a tree can block his line of fire, so that I don't need to go out of my way to tackle him. But there are other ways too.