I have often seen people comment on wanting additional differences between Wargs and Horses, besides a minor aesthetic difference. For example, horses have an excellent sense of smell and would likely get spooked if they smelled a large predator. Perhaps mounts could have their own morale, that could be broken. For example, not every horse is a destrier, your average mare wouldn't like the idea of riding toward fire. Magical walls of fire, or areas of the map soaked in oil and then ignited would be an excellent way to stop calvalry from flanking you. Having additional types of mounts with various degrees of training could make for more differentiation between units. A scout mounted on a palfrey would be more agile than a knight mounted on his destrier (which might even have it's own armor, further reducing agility while increasing defense). By contrast a Warg would get meaner the larger it was, and while a simple attack bonus is a nice way to show that the mount itself has the sort of sharp teeth that make it a formidable opponent in it's own right, perhaps there could be other consequences that Warg riders might have to take into account other than morale. One would imagine that predators wouldn't take kindly to being ridden, and might nip at their masters. They too would likely fear fire, but they would also have more difficulty crossing streams if they weren't as tall as horses, but perhaps they might do better with forests or other types of rugged terrain than a horse. And of course, what plea for mount variety would be complete if it didn't include the desire many people would have to use a Dragon as a mount, rather than simply another pawn on the battlefield, a sorcerer atop a dragon would be a mighty force to reckon with, capable of wreaking havoc amongst even the most hardened of enemy calvalry units.
So, rather than identical mounts with no real variation between them, perhaps you could acquire each mount and depending on some element of randomness you could add "perks" of a sort to even early mounts, provided their lineage was not that of your common plow horse. These perks could range from simple things like additional movement over passable terrain, to more complex concepts like putting a pair of blinders on your mount, or training it not to fear the smell of enemy Wargs. Wargs themselves could get older, larger, and meaner with time increasing their chances of snapping at enemy units (or friendly units, for that matter) dealing additional damage, adding bleed effects to their attacks, and perhaps even having a higher chance of snapping at an enemy mount, breaking it's morale and causing the horse to bolt with it's rider still mounted (or worse, thrown from the saddle and dazed).
I would love to see a number of summoner spells dedicated to mounts, a chariot of fire, a giant bird, a temporary wind walk "mount" that functioned only to transport you from one place to another and would be dispelled if you encountered an enemy... There are a great many possibilities for additional variation in mounts beyond even simple upgrades to the existing mounts. Also, it would give people a reason beyond the financial to consider having squads of infantry, if the enemy could simply lay out walls of fire to spook your cavalry (Also it'd be great if a large unit of infantry with tower shields could use something like the tortoise formation to shrug off enemy arrow fire, but be vulnerable to cavalry charges).
Having additional variety in mounts and additional reasons to use or eschew the use of mounts adds even the capability for the AI to adjust to the player's strategy, that fire shard never looked so appealing until you could use it to effectively prevent cavalry from flanking you. Of course, it would undoubtedly have the opposite effect at first, allowing the player to use complex strategies that the AI would wander right into. Still, sometimes you have to take a step back and regain your footing and take two strides toward your ultimate goal. The sorts of unit variety some people crave could easily be accomidated without additional races or fantasy units, simply by allowing more variety in the types of combat mounted soldiers could find themselves in. The enemy observers on wargs become that much more threatening to your unmounted infantry if after defeating the observers the Wargs themselves have to be attacked.
I realize that, especially when dealing with squads or companies of riders these more complex notions might be unattainable, but some destrier training, blinders, or horse armor don't really seem like they'd be too far out of line to hope for in one of the future versions of Elemental.
I have been away from the forums for quite awhile, so I apologize if some of this is simply rehashing discussion that has taken place in other threads in my absence, but I didn't find one reference to "mount" when I did a search, so something must be glitchy with the search.