That is a really good point Tim . It takes good stregth and lots of conditioning to run automatic tools all day long - day in and day out. Even the flat boxes and corner boxes takes strength and conditioning to use properly. AFWIW these tools really put the mud on faster than by hand. You still need to know how to manipulate the mud to make it look good with the least amount of sanding afterwards. So yes anybody can be trained to run these tools , but you cant do this trade unless you know how to use a knife or trowel properly and have the strength and stamina to do so.