[Cainehill]

There's really a lot of possible pretender choices that can get you rolling by somewhere in between turn 3 and 7. (Note that I don't say 3 and 5, because some nations & pretenders have a harder time doing the research needed.)

One key thing, early on, is that you don't try for provinces with certain troops guarding it (knights and heavy cavalry you already know; crossbows, longbows, barbarians and lizardmen you should also tread carefully with); you also don't take (most) pretenders alone into a province where there are too many troops.

Many reasons for that : fatigue, with most pretenders (albeit a high protection, high HP pretender can take provinces while "napping", with breath of winter and fire shield up); your defense is lowered for each attack (or attacker) past the first, so that 19 defense isn't too impressive when the sixth attacker swings.

There are exceptions : you can often take 70 troops early on with a good SC pretender, if it's only militia, light infantry, and archers. Of course - there might always be some wizards for commanders, so there's almost always a chance for death.

Some things that really help early expansion : huge protection rating, which is boosted by 1 for every point of earth magic. A 12 protection pretender with 9 points in earth magic has an impressive 21 armor rating, and a pretty good bless with some nations. He also has Earth Shards for negligable fatigue (10 or 20, divided by 8, plus encumbrance) and lots of rocks - awesome for militia, archers, barbarians, and other lightly armored types.

A high fear rating or high awe rating does wonders too, as the enemies either can't attack (awe) or rout quickly (fear). Being ethereal means that 3/4 of their blows pass through you with no damage.

Naturally having multiple attacks helps; having some tough minions in every battle can help or hurt, but does tend to keep your pretender from dying. (By tough minions, I refer to serpents, lions, etc, that have reasonable morale, and can't fly.)

Other things vary by nation : a high-fire Phoenix can romp with Marignon or Abysia, because each nation starts with a potent fire spell (Holy Pyre / Flare), and doesn't mind dying in friendly domain. Similarly, any high death pretender can do well with Ermor, scripting 5 casts of Summon Skeletons - the liches and vampire having an edge, because again, they don't mind dying.

And remember - not all nations need, or do best, with a solo SC. Some that have decent troops thrive by having the pretender go along with a small contingent of troops, or spell casting pretenders. Once Vanheim researches Evocation 2, a couple of lightning casting Van-commanders with a set of regular troops do wonders.

Biggest thing to remember - learn your pretender's strengths and weaknesses, and choose provinces to attack accordingly.