So I recently got back into playing dlr again (for the 4th time), but this time i really want to build my own army, ive never really had a clue which units to use and since multiplayer is hard to do its hard to really test, since its possible to win using just your hero and a few dragons. All i know is that i want to have the green dragon in the 7th slot and I don't want to use any mana or mercenaries. I like the general, the ranger, the vampire etc. i also dont mind having only 6 or 7 max in a stack. I always assumed that a good army should be able to fight on its own without a hero so i want to have all the different combat modifiers present. fear, chaos, fortify?, seige, morale.

my question is do these conditions lend themselves to any particular strategy?

Well you'll be wanting a cheap 1-turn ground unit that can be deployed en-masse to guard cities. Unless you are playing with fog of war/unexplored territory off you'll want a scout unit, cheap again, probably a flyer as well to go over difficult terrain and keep out of trouble.

You'll want an archer unit to take down flyers.

You'll want a 2 turn offensive unit to be assembled for massed assaults.

Then you'll want multiple support units, things like dragons, air elementals or catapults. These double up (except catapults) as a last resort unit incase anything gets through your screen of 1 turn defensive units. Don't double, you want as many different bonuses/penalties as you can.

Merceneries/Allies are best filled with the bonuses/penalties you don't already have as regular units.

The trick if you want to be really nasty is to mass stacks of 1-turn units inside a city with a small handful of support units at the back. The effect of these few units augments the cheap expendable units so that can take down units that are far more valuable without you risking your own valuable units.

Also remember the importance of morale if you are going up against undead.