So after I speedrunned each level on it's own, I gave the full campaign a try. I'm pretty happy with this time, it was only unfortunate that the last level had to go so bad :( The hardest levels are:

• The Spanish Treasure Fleet in Act I (500 att Delgado kills your mortar)
• Strange Alliances in Act II (RNG based British AI)
• The Boneguard's Lair in Act III (Many units to control and big fight in the end)
• The Last Stand of the Boneguard in Act III (Getting control of the fixed guns) (As you saw I messed up :P )