It really depends on what your goal is. And how your body reacts to the different workouts.
As mantence is much different then wanting to build more muscle, or lose weight.
Because to maintain you don't have to work so hard, as you already achieved your goal. It's kind of like getting on the freeway. When you start on that on ramp you got to speed up faster and faster until your fast enough to be able to merge with the other cars. Once you merge, and keep up with the follow you can sit back and just cruse, your not pushing the gas peddle more and more but basically holding it in the same spot. So your maintaining speed.
This is like maintaining your goals as well. If you already got all the muscle you want, lost all the weight you want. Then you can figure out a diet and workout program, burns just as much as you put in. And you maintain. A lot of times you'll workout less the whole week, and you can do the 3 total body workouts per week.
But if your trying to lose weight, you have to have a workout that burns more calories then you eat, so you have to workout more and harder, then if you just wanted one that kept you at the same weight.
Same goes if you want more muscle you got to work your muscles harder, and longer, which you can't do in a full body workout. As it's just impossible to work each part of the body individually and not make some stabilizers so you can exercise the other muscles. For example, you want to work your chest, if you do chest flies; it not only works your chest, but your bicep and triceps, as both are stabilizers for the weight. This if you try to work you bicep or triceps after your chest, they can't perform as much as they could if you had not worked the chest first. So say if you did your chest on Monday, and then your biceps & triceps on Tuesday. You would be able to work all three-body parts much harder, Monday & Tuesday, then if you would be able to, if you tried to work Chest, bicep & triceps all Monday.
So it really depends on your goals, as I have some very strong buff men who do a total body weight workout 3 days a week, do cardio the other 3, all workouts are an hour long, and that's it. They already achieved what they wanted, and now they can kick back with their exercise and just maintain. And they’ve been able to keep their results and fitness level with that type of schedule, for over 14 months. So it is, possible once you reach your goals.
I personally like to look at Cathe's split workouts as goal setting, you can maintain with them, but it's a bit harder to maintain and not want to do achieve a little bit more, when your looking at Cathe and crew. And thinking well I achieved this, I think I'll try to look like (fill in name of your favorie backgrounder or Cathe).
As Cathe does have some circuit workouts that you can use for your maintance if you want more all over type of thing rather then a split.
Kit
