In this case, 重裝甲的賽連的機動力應該會比輕裝甲的賽連高.
Since the equipments and armory of both 賽連s are different.
Heavy Armor 賽連 with left arm-guard: It would gain more speed than normal version since an arm-guard is less heavier than the full set of heavy armor.

Light Armor 賽連 with shield: It would become more sluggish in speed if the shield has to be an add-on equipment. The design of Light Armor 賽連通常用於游擊戰, since its mobility with the orginal equipment.

Conclusion: Heavy Armor 賽連 would be a winner.

PS: However, the confidences of the pilots and fatimas are also factors which would affect the final result.