One issue I frequently encounter with teaching and training in an internal kung fu style is training for health vs training for martial proficiency. The issue comes up particularly with people who come to me looking for instruction in "tai chi." They often come with the perception of tai chi as a gentle, slow paced, transcendental dance performed by old people in the park. That's all fine and good, but that preconception is disconnected from the reality of learning a martial art. Even if one only wants to train for health purposes, learning the art properly still requires exposure to the martial aspects of the art.
Training for health vs martial proficiency is nonsensical dichotomy. Both are present in the training; you can emphasize one or the other, but you cannot totally ignore the health or martial aspects. If you train to fight, you will be improving your physical conditioning, but you will still need to learn the health improvement aspects of the training. Learning to rejuvenate and heal the body is necessary to recover from the rigors of the martial training. For those training for health purposes, exposure to the martial side of the art is still important to put the movements into context. Without any understanding of what the movements are meant to accomplish, practice of the movements becomes an empty choreography. Just going through the motions as a pre-choreographed sequence will still have health benefits, as would almost any activity involving movement and breathing. But doing the movements as a dance will no longer be training the art.
Martial and health-focused training both require the same foundational skills. Both tracks require the same mental training. The ability to focus the mind and pay attention to the body will be the same in either case. On the physical side, both martial and health training will also have a common foundation. Since we exist in a world where we physically move and act on our environment, movements are trained to accomplish some physical task with our bodies, like pulling, pushing, throwing, jumping, etc. Studying body movement requires training kinesthetic sense, balance, alignment, muscle activation, joint mobility, body unification, etc. Training for martial or health purposes might change the context or intensity of movement, but it doesn't change the fact that you're training the body to move.
The issue of partner training often comes up in the health vs martial training split. While it is true that partner training begins to veer more towards the martial side, it still serves a purpose in non-combative training. Interacting with a partner is still a meditative exercise, particularly at the lower level drills. You still need to pay attention to your body unification, but now you also have to expand your attentions from yourself outwards. With another person in the equation, you have to maintain your mind in the moment to both maintain your body unification and to flow with your partner. Even in more overtly martial partner interactions, you are receiving kinesthetic feedback from your partner which help improve your movement ability. With an external force acting on you, you can more clearly feel whether your body mechanics are working properly; while some movements may feel fine practiced solo, they may not feel right in partner interactions. The physical feedback from a partner allows you to perceive and then correct and fine tune alignment and body unification issues.
In the end, training for health or for martial purposes is an unnecessary distinction. The split doesn't become important until partner training, and then only after the partner training progresses to being more overtly martial. Both tracks are built on the same foundation: training the mind and training body movement. For a large part of the training, the learning process for the two tracks will be similar.