Partner training drills help the player to find powers trained individually. They should not be used to train the power, but to test the power. The drills are friendly, but not overly cooperative. Considerable force needs to be used to test the powers and skills of each player.
Traditionally, one should search out a partner much stronger than you, a partner much weaker than you, and a partner about your equal. Each can teach you something about your skills. Someone way beyond your skill/power level will give you a feel for what whole body power is. Someone at your own level gives you a chance to find the power yourself. And you need to practice with someone below your level so you can feel what it is like to apply the power.
Partner training drills are repeated for a long time to fully find the power and help change the body. In the partner drills it is important to use the whole body power developed in the bear walking, and not to get carried away with trying to 'get' your partner.
The Ma Gui system places some emphasis on Yin Fu's spearing palm, but it also trains many other techniques and has other training methods.