MosheLevi is obviously thinking from the point of view of an attacker. I will counter with a question:
-If the AI were to declare war on you with a SOD on the border capable of taking your cities, would you want them to be able to use your roads/rail, and thereby take multiple cities before you have a chance to react (remember, civ is turn based, not real time, so you have to wait for your turn before you do anything)?
Players can already do that with cities that are near their border.
For that reason players have to place many units in cities that are near a border with another CIV.
A strategy that I like to use is placing a large stack of units a few tiles behind two cities (that are near a border) where all these units have multiple “City Attack” promotions (including many artillery units).
If the enemy takes one of my cities by surprise I will then attack his SoD with my large SoD the next turn where the advantage is on my side (due to the multiple city attack promotions).
Here is my proposal for unit movement:
Infantry – 2 tile movement in enemy territory via roads (instead of 1).
Tanks, Tech infantry, Mobile SAM (and other vehicles) – 4 tile movement in enemy territory via roads (instead of 2).
Gunships - 6 tile movement in enemy territory (instead of 4).
In friendly territory units can move 10+ tiles but cannot attack on the same turn.
For attack they use the same rules as above.
I agree that this gives attackers an advantage.
However, this can be balanced via other two proposed features that we talked about in other threads.
1 – Implementing “Ambush” ability so we can ambush incoming SoD’s causing massive casualties (guerilla style).
2 – Increasing the number of units that suffer collateral damage (based on percentage) on the field (not in the city).
This will make large SoD’s more vulnerable to collateral damage.
I have played other Turn Base games where unit movement and maneuvering was important part of the tactics.
This aspect is not too advanced in Civ 4.
IMO, to make battles more tactical the tile attack movement cannot be huge (e.g. 10+) and SoD’s should not be huge and invulnerable.
CIV 5 will be more interesting if we have more stacks with limited mobility where maneuverability counts.
Take for example the “Total War” series.
They have the same movement in enemy territory and friendly territory.
They also have limited stacks.
Now I am not in favor for hard limit for stack size.
However, I believe in consequences for having too large stacks (via higher collateral damage).
Playing “Rome: Total War” and then later “Medieval 2: Total War” I always felt that I have many choices when I decide to invade another CIV.
That is not the case with Civ 4.
With Civ 4 I feel my options are limited.