If I take "what you could see off the battlefield" correctly to mean, while campaigning, the advantages of a mount would include, not least, not having to walk! I think most company officers sought to find themselves a horse or mule, if they could afford it. Maintaining it certainly was financially burdensome for many, and seasonal or geographic difficulties of forage added to a high loss rate (and, thus, added costs)!
Surtees, in his lowly-almost-an-officer role complains of the cost of keeping one and lack of appreciation by a senior officer of how important for his duties having a horse was.
Or did you have something closer to the battlefield in mind? Oroff the route of march?!
Cheers - Howie