In mechanism dynamics you can use gear pairs with offset distance to simulate a rope wheel system while in mechanica you can use springs to simulate rope.
Just one observation: how do you take into account the slip? What about tensile forces on the belt, friction between belt and pulley, and belt elongation due to belt load?
You can,t compare MDO with ADAMS which is a dedicated software. Gear pair in MDO only takes into account the velocity ratio, although you can add damper and springs and friction (both staic and dynamic) as well.