Eh. It might not be optimal, but at least it's interesting.
Sadly I don't think ranged mounted combat is a thing. Only thing more hilarious than blasting things with a spell and a volley of arrows in the same turn is doing it while mounted on a dragon that has 60 feet of movement per turn.
Though it's probably a bad idea, considering that I've observed that mounted combat currently involves merging the animal companion and rider's turns into one, so you can't do something like, say, move using the animal companion's turn and still get full attacks with the rider. Having Seelah riding her mount in combat came with a significant downside in that her mount lost the ability to trip enemies while she was riding it (assuming you built her animal companion for that), though it had other just as significant upsides such as essentially eliminating her movement speed penalty from heavy armour.
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o.O That´s not exactly how it works. your wolf or leopard could still trip or trample or sunder armor, power attack. You just have to switch it the auto-sunder in the animal companion action bar. The wolf, leopard, etc trips automatically when you attack.
Besides the fact that you have the mobility of your mount (that usually doubles the land speed of an armoured character) the way they made flanking in the videogame, when you mount you are always flanking the enemy (i.e two allies are threatening the enemy) so +2/+4/+6 to your attacks, plus you automatically have all the teamwork feats on (because technically you are sharing your space with an "ally"), like precise strike that ads 1d6 to the damage, coordinated manoeuvres that gives bonuses to trip attacks, etc.
That adds to the +1 ac and +1 to attack to enemies less than large size when you are mounting a horse, and the mounted feats that you can learn to use when you are mounted.
Now drawbacks... uh... The one I can think of is that you move both characters in the same turn, if it is a disadvantage... and the fact that the enemies attack your mount first, but it could be fine to use your companion as a meat shield. I cannot think of any other "disadvantages", and it´s not really a disadvantage most of the time, and if it comes to that, you can just dismount.
The only thing you cannot use is the breath cone attack of one of them,(at least in the beta) the azata dragon companion that you only get taking the Azata path, because you cannot aim the cone when you are mounting it. But you can simply dismount in the middle of the combat and then mount again. You can actually mount Aivu in the beta 3, and now in the final version of the game.
