not sure if this is bug or feature.

but it makes the gauls incredibly powerful in the campaign. forester's produced in valor 3 cities and upgraded in missile 3 cities are strong enough (missile 21). With the melee upgrade, their melee attack is at a ridiculous 17 (charge 8), so even if the enemy manages to engage in melee, odds are the foresters will destroy them.

If this works on spanish bull warriors (don't see why it wouldn't), then i imagine spain would be similarly powerful.