It is, of course, possible that both men knew each other - but [and it's a big but] you have to remember the numbers we're dealing with here. Well over 100,000 men would have enlisted in September 1914 - well over 100, 000 men went over the top on the first day of the Somme - 60,000 + casualties in the day, and literally hundreds went through Alnwick Camp. So. it's possible - but it's probably the case that they did not know each other.
jds1949