Warrior Ancient and Medieval Rules

I'd still like to talk about this terrain stuff.
Generally I'd like have something created that
encourages "characteristic" terrain for at least one army on the field.

I had some ideas over the weekend to encourage historical terrain
selection. They need some work still, more experienced players and
more knowledgeable geographers would come in very handy in flushing
out the details.

Instead of the usual +1 for climate advantage, armies would roll-off
to determine who was invading and who was deffending.
The deffenders climate would then influence terrain picks.
Say:
Dry -- a woods penalty roll of -1, dunes bonus +1(placed without mwf)
Warm -- a woods penalty of -1, bonus for orchards, olive groves
Cold -- no change
Tropical -- a woods bonus of +1, a minor water feature bonus

Something like this.
Like I said, needs work.

The result would be:
-at least one army would be fighting in characteristic terrain.
-armies are prevented from relying on the same terrain choices.
-players would be forced to think on their feet (even more).

Any other suggestions, comments?

Noel.