Such horses are usually docile and not easily frightened by anything. They don't often have to move heavy loads, although at times they might be called on to pull some extra weight. As a result of not caring much about anything, they may not care if a heavy load comes or not. Logging horses, on the other hand, are often asked to pull all they are capable of pulling. Every horse has its limit, and if one can't pull a particular load you will have to go do something time-consuming to get the load to the landing.
Time is money in any production job such as logging.
A horse with a good deal of determination to go ahead on a load may be more difficult to handle and keep headed in the right direction. The animal may not make a good farming horse if it is a sizzling mover and always wants to go faster. For farming you need a gentle team that doesn't much care what happens. For logging you need a team with determination to go ahead. Some horses are good all-around horses that will do well in either situation.