This paper concerns itself with identifying and addressing challenges in high school-level teaching with real-time cross-device collaborative interactions. Specifically, it identifies a challenge of inappropriate workload distributions within student groups within these interactions and presents a concrete learning activity with elements specifically designed to combat this challenge. These elements are based on a notion of limiting the innate freedom of a model shared real-time by introducing carefully chosen constraints in the various ways of viewing the shared model, with the goal of making collaboration the path of least resistance in achieving a goal. The paper discusses and evaluates the approach and choice of constraint by carrying out the learning activity in real classroom settings.