Bagh. What mechanic stops you from just making a two, three, or four-square army?
The fact that you can only attack with one stack at a time and the fact that the defender moves first. This means you could potentially attack with 8 stacks of 9 (72 units total) and the defender would move first in each combat. If his defense was strong with the right units, he could wipe out each of your stacks before you get to move, allowing him to wipe out your whole army without taking any losses.
Considering what I just said, that's a pretty big caveat. Nine defenders versus potentially 144 attackers (that's assuming a 4-by-4 square, which is about the biggest thing you would probably get in a single turn, considering movement points).
See above.
And, HOW big are these nodes again? If it's a huge field of energy, I could see this being of value, but other than that.....
Nodes are 1 square in size, just like cities (in MoM).
Methinks thou hast missed the point of "heartripping". You don't always have to go for the channeler: you take out powerful cities like econ or research centers, and cripple some stat or the other.
What's the problem then, exactly? I would consider this to be a basic strategy. You also need to factor in the terrain. The attacker may be forced to go through chokepoints to reach the defender's "heart".
Research in MoM couldn't really be stacked up in one city, by the way. Essentially every city contributed a small amount of research, with the rest coming from your total mana intake.
Well, that would certainly help, but it would be mighty hard to eliminate the problem just with increases detection. You still have to send a significantly powerful defense force to whichever juicy target the other guy selects. If you guessed right and stationed your forces there ahead of time, then good for you. If not, then you're still in trouble.
With enchanted roads and recall spells, you don't need to guess at all, since you can move your defenders faster than he can move his attackers.
Flip side of the same coin, if the attacker has invisible units, you're in a boatload of trouble.
No, you aren't. As the defender you are under no obligation to defeat the attacker's forces. If he cannot defeat your defending units, he cannot take the city. An invisible unit that cannot defeat the defenders is useless (unless you are using certain spell combos). Battles in MoM that lasted more than 50 turns automatically resulted in the attackers retreating.
Again, the flip side problem. You have to wait until the enemy is right on top of you to cast a spoell to get rid of him/her.
No, you don't. There are powerful overland spells that can wipe out enemy armies outside of combat. There is even the truly awesome Meteor Storms spell which bombards with strength 4 fireballs all units in the world which are not in the safety of a city garrison, every single turn. With this spell, you can "turtle up" and your enemy will have an almost impossible time moving his units around the map.
We have NO assurances that EWOM will even remotely resemble MoM. All of these mechanics could appear in the game, or none of them could. Even if they did reappear, the differences in other areas like algorythms, mana generation, units, and general working of the game would likely distort the effect on gameplay.
A red herring. I have no idea what EWoM will actually be like. All I can talk about is what I know, especially about MoM and TBS in general. I've done my best to describe the many different mechanics in MoM and how they work. I believe that most of the mechanics in MoM are heavily interdependent and pretty well balanced (some things need to be tweaked, I know). Because of this interdependence, you cannot really take the mechanics out of context lest you throw everything out of whack.
No, no no no dear god no! This is exactly what creates the AoW style stack of doom instead, where you just load up a stack with the strongest unit you can possibly make, and nothing can stop it except a stack of the strongest unit on the other side. It obsoletes everything other then elite units.
Artificial stack limits make the problem even worse. What's needed are situations where it's actually worth splitting your army up into multiple groups (which was almost never true in Civ 4 unless you were at war on more then one front).
Another red herring. A properly balanced game does not have a "strongest unit", it has many units which offset eachother in a rock-paper-scissors fashion. Therefore, your 9 unit stack might have 3 rocks, 3 papers, 3 scissors against the defender's 3 rocks, 3 papers and 3 scissors. How is the combat resolved? Tactically, with the best tactician winning the fight, although the defender has a big advantage in moving first, potentially cheaper spells (channeling) and city defenses.
Without stack limits, all of the strategy is thrown out the window in favour of who can mass the biggest stack of doom. You might want to peruse the Civfanatics forums and see how many people complain about stacks with "hundreds of units" being impossible to defeat.