snepp said:
It depends on the situation, here's a couple things to consider (not you specifically, just anyone in general).
Catapults cause collateral damage to 6 units, Cannons to 7, and Artillery to 8. This is in addition to any damage to the unit they attack (or possibly kill).
Yes, collateral damage will get spread out over a SOD. The first catapult will damage 6 units, the 2nd catapult will damage 6 healthy units, and so forth. I don't think this is a hard and fast rule, but it typically works out this way.
How many siege units does the defender have in the city? Let's say you have 16 units in your SOD. If they've got 2 catapults they could potentially cause damage to 14 of your units. Now separate that stack into 4 stacks of 4 units, this cuts the potential number of damaged units down to 8, make it 4 if they throw both cats at the same stack.
Let's say in the last example they throw both both cats at one stack and manage to kill them off. You're left with 12 fully healthy units vs having 2 healthy and 14 damaged in a SOD. The particular situation is going to dictate which situation is better. Alot of weaker units defending, strong but fewer defenders, the amount of collateral damage you're capable of dealing, etc etc.
You are correct, the situation must dictate what you do, and you need to adapt to survive. There are way too many factors to list and discuss. Relative tech levels, offensive or defensive minded units, terrain that your units are on, etc. I just personally have not come accross many situations where I felt, in my opinion, that it was advantageous for me to separate my SOD. I would rather stop and heal many or all my units, rather than lose a few units and have to replace them, while the rest of my units are completely healthy. Smaller stacks can be vulnerable to being eliminated. If the AI has the firepower to eliminate your SOD, then he certainly has the frepower to eliminate many smaller stacks.
One situation for sure where you WOULD want to separate into many small stacks would be something like this: You are attacking an isolated city with 2 archers, and 8 catapults. Your SOD is say 16 mixed swords and axes. If you go in with as an SOD, you will lose anywhere from 3 - 5 units from the cats, and may not be able to take the city. But if you separate into 8 stacks of 2 each, then you will take probably only take 2 - 4 losses total after taking the city. But this is an extreme example, and assumes the AI attacks with the cats, rather than defends.
I play large maps mostly on Prince, sometimes Noble to try something new. I have no idea if my theory holds true on higher difficulties or not.
How I use siege equipment:
As soon as cities are defended by lonbows or better, i always include 4-8 siege engines in my SOD. I first bombard to eliminate city defense. Depending on number and quality of defenders, and how many units were used for a complete reduction of city defenses, I may wait until next turn to attack. Whe I do attack, I typically use 1-4 siege units for collateral damage, then attack with melee / mounted types. At this point in time, siege units are cheap and easy to supply, and are generally expendable.
This changes with the advent of the tank. At this point, I only use siege units (artillery) for eliminating city defenses, and I typically have 6-8 in my SOD. I then use the tanks to attack for collateral damage. I usually only lose 1 tank, maybe 2 (many times none) before the damage snowballs into a mop-up deal. Here's why I do this: It's much easier to get a replacement tank to the front lines than it is an artillery unit, and they cost about the same to make. If you do not have enough artillery in a stack, your advance will be slowed dramatically, or you will take more significant losses.
In general, combat in Civ IV is a much slower affair. I have not even sniffed a military victory on the bottom side of 1800AD. Of course, I may not be any good at Civ IV...
