Rough, rougher, roughest

Mercury has been a little sensitive on his feet, but he's been getting turned out, and I rode him yesterday for the first time in two months. He was an angel. I didn't even lunge him first. I took him on a walking only trail ride, and he got a little nervous (especially because there were two horses cantering around), but he was totally sweet. He is such a good, reliable horse.
In contrast, Willig's hives came back, he was jumping up and down in the cross ties, he got moved to the closest turn-out (which means, I think, that staff is still having trouble leading him), and then, just to keep me on my toes, he was totally calm and good when I lunged him and then rode him.
The hives are along his side and lower neck - not under his belly, but on the lower half of his belly/side. They look just like they did before. There are more than a few, but not so many that they're touching.
I bought him yet more herbs, because apparently two horses and two dogs and three cats are going to drive me broke this year. This time I got him the "relaxation" blend. He just doesn't seem like a high strung horse to me (ignoring the jumping up and down in the cross ties) - a thoroughbred (ignoring the paragraph about Mercury at the top) is a high strung horse; not a warmblood.
I really - after relaxation herbs - I have no more ideas.