Tactics and strategy in Heroes of Might and Magic V.

When I play as Orcs, I always do the following:

1) I buy a tavern. This allows me to buy 2 heroes (if there's only 1) and give the army of the second hero to the first. This makes the first hero stronger. Another reason I buy a tavern first is curiosity. I agree, it's nice to know that your hero is in 1st place.
2) I buy a Centaur pasture. It's a big advantage to buy archers. If the enemy can't shoot, their unit just walks around aimlessly, while you take them down.
3) I buy Goblins.
4) I upgrade the Goblins to Trappers. They complement the Centaurs well. The Goblins set a trap, preferably nearby, so that the enemy unit doesn't move much, and the Centaurs take them down in the meantime.
5) I buy a building where machines are built.
6) I buy a level 3 unit, I forgot what it's called.
7) I upgrade the level 3 unit. (This is optional, depending on what you want to do.)

After that, I don't have a fixed tactic.