[Endoperez]

What was the level of independents? The default is pretty low, playing with level 6 gives you much more time to get
ready for the enemy, and slows the AI down more than it does you.

The national units are just the beginning. Research and magic is where the true depth is, as well as the diversity of nations and magic paths. And if you get to like the game, you can start choosing from the nations and spells and items and creatures, and play the game your way. To get to that point, well... the manual is mostly just listing all the spells and the items. Quickly look through the index, and check those that sound interesting (like Vision's Foe, eye-eating crossbow, or Blade Wind, that fires 52+ low-damage missiles in one casting). Remember that a + after a number (damage, Area of Effect, etc) means the power grows with better mage. Thus Falling Frost (AoE: 5+ and damage: 17+) will be a monster if cast by a mage with Water 6, which is not too hard to get. Choosing what to research can be quite hard in the beginning, so just research Evocation, mainly consisting of different combat spells. It suits any nation with elemental mages, and quite a few others. Other options could be Conjuration for summoning, Enchantment for raising the dead, or Thaumaturgy for Astral mages, with Paralyze and Mind Burn. Preferably you can then have your cheaper mages cast something offensive, like Fireball (Evoc. 3, Fire 2), Magma Bolts (Evoc. 3, Earth 1 Fire 1) or Mind Burn (Thaum. 2, Astral 2).

Defending your area can be quite hard. Buy some Province Defence, but not much. Few points are enough. On provinces next to enemy border, buy 11 points of pd. This will discourage your enemy from attacking your provinces, as there are some defenders there.

If you were to try with other nation, try Abysia. They have pretty strong starting units, get extra points by taking Heat 3, and start with pretty good Fire-based attack spell, Flare, researched. Abysia has no archers, but if you pretender has at least Fire 4 and more than 15 hitpoints, he can be used to scorch early independents.