Former Celtic boss Martin O’Neill mastered the art of winning the Scottish Premiership title in his five excellent years at Parkhead. Three league winners’ medals symbolise the power of his reign in Glasgow’s east end, complemented by a trio of Scottish Cup trophies, one Scottish League Cup and our famed run to the UEFA Cup final circa 2003. In short, O’Neill has seen it all at Celtic, and his opinion ranks among the highest regarded by the wider support whenever he is asked about his old club in media circles. The Bhoys have been Scotland’s dominant side in every metric of the domestic game, …