GOGwiiisfun: Hmm, I've certainly defeated armies with multiple tier four creatures with a scout and although I rarely run into the type of fights that you've described (some of the 'cult' armies and druid/forest armies), I think that it'd be possible to defeat them. Although you might lose a few of your veteran units which are very important for a scout.
Something that is crucial to your scout being able to take on some of the more difficult fights is veteran units. A scout needs a wall of veteran units to be able to take on some of the more difficult fights. The units in question are usually swordsmen combined with veteran healers (or any other type of unit with healing abilities). Swordsmen are good because you can start training them and using them very early (because they are tier 1 units) combined with the fact that they are ridiculously powerful for tier 1 units with the right metals and a decent level.
A swordsman with the right metals and a decent level can defeat almost any tier 1+2 unit on it's own, defeat most tier 3 units with the help of a healer, and even take a few hits from a tier 4 unit which gives the scout time to take it out!
Oh and swordsmen, the game will not abide leveling them up. But one time i tried leveling a few up by keeping them behind, just to see what they can do, and what they do is go 'poof' the moment you dare to try and use them! USELESS. They have one purpose in the game, and that is to die as green inexperienced scum and be replaced as green inexperienced scum.