Rangers fans know all too well that, when it comes to centre-forwards, you often have to take the rough with the smooth. For all of Alfredo Morelos’ qualities, consistency wasn’t really one of them. The firebrand Colombian did not even break the 20-goal barrier in any of his five Scottish Premiership seasons. As for Cyriel Dessers, while the likes of Lawrence Shankland continue to feast on goals, Rangers‘ current number nine has endured the odd famine. Dessers did hit the target 22 times during a mixed debut season at Ibrox. But, given the quality of the chances he squandered, it is no stretch…