People do plateau. The body only improves to the point necessary to meet a given challenge. If the challenge doesn't increase, neither does their fitness level. Walking 10 minutes a day will produce fitness benefits. Those benefits do not gradually increase without end. The same goes for bicep curls with 10 pound weights, at 10 repetitions.fitness is an ability to do,,
if you go to a lab they will assess it by measuring your vo2 max, ie your ability to metabolise oxygen, with out which most of your doing will be very in effective ,
at a more general level it must involve the basic elements of human activerty, so that's cardio,strengh, endurance, co ordination balance speed mobility/ flexability. If your not providing them with a method to improve all them then you are,dropping short on providing them with general fitness ,
in a martial context, then if you sent providing them with the above in a ratio that applicable to the,style of fighting, then you are again selling them short
people don't plateau, that's a biological impossibility, they are either very slowly improving or very slowly reducing in fitness' ( as defined above) and if they have," plateau" because the exercise's are no longer,challenging them, then they are reducing in fitness and will do so, till they reach a level were the exercise's again,challenge them
As for the rest, it sounds a lot like you're trying to criticize a vaguely mentioned regimen. I am not a fitness center. I include an amount of fitness in the training, to help students develop a baseline of fitness. If they have a specific need, that's their responsibility, and that was my point. What I provide (in the area of fitness) is what I consider minimal. If I were to offer fitness classes, I'd take a different approach.