Celtic have endured mixed fortunes with their arrivals over the last couple of transfer windows since Brendan Rodgers returned to Parkhead. Luis Palma has been arguably the most consistent of their summer incomings; meanwhile, Paulo Bernardo and Hyunjun Yang have shown moments suggesting they could be part of the long-term framework. Nevertheless, there has been frustration from the support at those who haven’t hit the mark, or, more to the point, individuals who barely got their Celtic career off the ground before being farmed out on loan, such as Hyeokkyu Kwon and Marco Tilio. In the January…