I guess the biggest Dom2 guru would be Zen but he isn't always around. But nothing beats having the developers themselves answer your questions on the Dom2 forums, which they often do (though sometimes they forget what they put into the code
)
Some of your questions:
- Placements of troops.
Whatever makes common sense I suppose. If you have missile troops and your enemy does not, you want to put them way back and slightly to one side (to avoid them firing over the heads of your own troops) and have your melee tanks (heavy infantry types) on hold and attack orders to maximize the number of shots your own troops get off before engagement. If your enemy has missile troops and you do not, you want your troops as front as possible to engage their archers quickly and so forth.
Placement of mages depends heavily on what spells you want them to cast and the ranges of those spells.
- Scripting
This is sort of like SEIV strategies for normal troops. But it is most important for mages because you can control the first 5 spells that they cast using this. After that, the combat AI chooses for you.
- Research
Like you said, it all depends on what your overall strategy will be and what nation you're playing. When I first started playing Dom2, I thought that combat spells did very little compared to troops. I mean, give me a troop of longbows over a couple of mages casting fire flies any day, and the troop of longbowmen will be a lot less expensive.
But later in the game, you'll see spells like "Blade Wind" (chews through massed concentrations of low armored troops, like most missile troops, shockingly fast), "Wrathful Skies" (destroys any conventional army just like that, really) etc.
I think that when you get into Dom2, one mindset that you need to get rid of is to think about creating an empire in the way that you create an empire in SEIV. Really, Dom2 is all about pure offense so provinces change hands all the time. The only really essential province is your capital because that is where your capital-only mages can be recruited. There are no safe backwater provinces in Dom2, so don't get upset when you lose a bunch of provinces in a single turn. You just take them back.
Forget too about shepherding your people to a safe and prosperous future. By the time the game ends, the world will likely be a bLasted, depopulated landscape filled with all manner of undead, monsters and other weird things.
Also, luck and chance plays a bigger role in Dom2 than in SEIV. If you're not comfortable with that, then Dom2 isn't your game. Random placement of magic sites, which nation you start next to, random events, what independent mages you find to recruit etc. has a huge impact on the game. In one MP game, my lab burned down on turn 4 which set me back a whole lot due to the cost of rebuilding. In one current MP game as Ermor (who has no money), my temple burned down twice!! within the first ten turns. It was incredibly demoralizing.
The graphics in Dom2 may be crappy, but the battle replays, when you have lots of high-end summons, and all sorts of battle magic, and super combatants carrying powerful artifacts, can be incredibly entertaining to watch. Pulling off cool spell combos with the right kinds of troops is really very satisfying.