It is the interaction of energy between 2 or more people which helps you develop IMA.
Without that interaction , you have no clue what your even working on, that interaction does not include ego building or who can beat each other up, that does not help you to develop yourself, that just leads to big head and no IMA development.
The goal is develop internal, other benefits like application will naturally develop , but practicing and developing is different from testing, you can test, but that is all your doing, then go back to developing .