Last chapter difficulty spike

[Knight who says Ni]

Playing on highest difficulty. OK, sure, its the last chapter so should be difficult. But armour 9 units, and loads of units with resilience that stay on the map plus units that spawn more copies of themselves that you cant kill because of said armour, seriously?

I mean some of the vampire battles in the previous chapter were tough but I was able to overcome them with a bit of thought, other than puzzle battles I never needed more than 2 tries to get past. How do you overcome the ridiculous cheese of this though?