How did Trooper Warren treat Joey?

According to Joey, Trooper Warren was a terrible horseman but the gentlest of men.

Trooper Warren was not a good horseman – I could tell that the minute he mounted me. He was always tense and rode me heavy in the saddle like a sack of potatoes. He had neither the experience and confidence of Corporal Samuel Perkins nor the finesse and sensitivity of Captain Nicholls. He rocked unevenly in the saddle and rode me always on too tight a rein so that I was forced to toss my head continuously to loosen it. But once out of the saddle he was the gentlest of men. He was meticulous and kind in his grooming and attended at once to my frequent and painful saddle sores, chafings and windgalls to which I was particularly prone. He cared for me as no one had since I left home. Over the next few months it was his loving attention that was to keep me alive.