Simplest way to mark distance before a charge?

Hey all, just asking a few quick questions.

I've been playing as Hayasdan -- classical times were Armenia's finest years -- and I've been wondering if there is an easy way to judge the distance at which I can charge horses. Now for something that can be easily answered: can I charge horses while inside a settlement? Seems simple, I know, but I've had a run of pitiful charges, really should call them trots. I'm sure it's actually a matter of distance as none of the horsemen were engaged with the enemy, but they were <i>pretty</i> far back along the small street.

Charges rarely work inside a settlement. Narrow streets mess up their dressing, and besides which it works better if they can maintain a broad front.

I've been able to charge in the plaza, given enough distance. You'll need at least a large town if I'm not mistaken, along with the right moves/positioning. As for the simplest way to mark distance: experience. Given enough experience (read: practice) you can almost consistently nail the charge distance to lower lances.

Another thing that can mess up charges is pathfinding. Your units should be no wider than the actual street (the pavement) or else the engine will continually try change the depth of the formation. Street width can be hard to guess in barbarian towns, but is actually the same as in civilized towns, so just use the same unit width there.