First impressions count for a lot in football, and a couple of Rangers’ summer signings have made a pretty good one. According to former striker Kris Boyd, Connor Barron was the stand-out performer during Saturday’s 0-0 curtain-raiser at Heats. Philippe Clement did not go quite that far – the former Aberdeen midfielder, he said, had performed better than that in pre-season – but this was a strong start from the potential long-term Ryan Jack replacement. Vaclav Cerny also impressed Clement off the bench at Tynecastle. Lightning struck twice as far as he was concerned three days later in Poland,…