I could “do” two horses in 1 1/2 hours. I do a lot of trail for conditioning, sanity, and variation, so I can ride one and pony the other easily in that time. `My horses look great, but I literally spend almost no time brushing them except to make sure the saddle area is clean. They are in pasture, so I throw them out there when done. If it’s hot and they are sweaty, I hose them off. That doesn’t take long.
If I am pushing time and riding both, I can warm up both on a short trail, take both to the arena, tie one and ride the other for maybe 20 to 30 minutes. They wear the same saddle and bridle, so just switch horses and do the other. The real work I am doing is really no more than 30 minutes. I am not doing 45 minutes to an hour of piaffe/extended trot or changes. I can do that in two hours.
Maybe it’s because mine are not in stalls and moving all of the time, so I don’t have to take that extra long time to make sure they’re super warmed up before working?