Reddit mentions of Charley's War: A Boy Soldier in the Great War

I'm sorry I missed this!

It's a remarkable strip, and very well-liked by many in the world of First World War studies. I assume you're looking at this recent Titan Books reprint that's been made widely available (but do correct me if I'm wrong!). It's a great starting point for the series as a whole, which currently runs to some ten hardcover volumes; this one collects most of volumes 1 through 4.

The series is very "realistic" in its depictions of how appalling conditions in the trenches and how chaotic such combat could be, and it is very much focused on the experience of the regular fighting man rather than the wider geopolitical ramifications of everything. It's one of the very few comic strips I've ever heard of to have been given an official research budget, in any event, so I hope that gives you some impression of how seriously Mills and Colquhoun took their business. Still, it's very much a part of the long-established "mud, blood, and futility" school of First World War works, so take that for whatever it may mean to your father.

In short, I would very happily recommend it, and also very happily own it. Another such work that might be very much looking into is Jacques Tardi's It Was the War of the Trenches and Goddamn This War!, both of which are amazing and both of which have recently been republished (and translated into English) in a handsome two-volume hardcover.

I do not really recommend Joe Sacco's The Great War, but it's still an impressive work for all its flaws.