I actually had a tactically challenging battle in Empire Total War. Usually in empire you simply make a line. The enemy will charge headlong (often in clumps) into my line and they'll be destroyed. But in this battle I was defending against Wurttemberg. By random chance the enemy army had like 50 guns. Far more than what is common in the game. This was quite epic. With 50 cannon and howitzers incoming and some 20 outgoing, it was a beautiful sight. Two of my battalions were decimated by this. Another surprising thing, the enemy actually tried to flank me(twice!)
First they attack through some woods, my unit unit there is a severally weakened unit of legion Britannica. It's chased out, and some Wurttemberg grenadier hit my line on the other side of the woods the same line that got battered by the bombardment.
Things are looking bad, my reserve in that area is 4 badly damaged battalions I only planed on using as guards for my artillery. I send them to meet this threat. But even further on the same flank 3 Wurttemberg battalions are trying to circumvent my entire line. I have nothing to stop them with and I can only hope I can chase off the grenadiers and their supporting battalions before this flanking force hits me.
On the lighter side my left flank (grenadier brigade and cavalry brigade) is untouched.
My cavalry brigadier is itching to charge those 50 guns but there's still 3 battalions and 3 cavalry regiment between him and this bronze monsters.
There is nothing for it but to advance my grenadiers. This is when the AI goes into it's usually shenanigans. The enemy dragoons charge straight ahead and as usual gets shot to pieces. The milita battalions left in front of of the grenadiers are no opposition and gets brushed aside. The cavalry brigadier gleefully charges the guns and for good measure the grenadiers join in.
On the more problematic right flank. Things are chaotic. My two battalions that first were exposed to 50 guns then flank attack. Have run for it. Lucky my 4 artillery guarding battalions did a great job and with the help of some dragoons and close range canister form a 4 gun battery. Defeats some 9 enemy battalions. Things are looking stable when suddenly from nowhere my big howitzer battery is attacked from behind by enemy dragoons.
My only option is to send in my now weakened dragoons and the 3rd Duke of Marlborough with his bodyguards. The dragoons gets taken care of. But my battery looses 3/4 of it's crew.
By now the enemy guns are neutralised and the last enemy battalion is running for it.
It's one of the toughest fights I've ever had in Empire. I was lucky that 50% of the enemy infantry was milita.
I still lost 50% casualties.