For once, I gotta agree with Willy. The tech is gonna be a bit "Schizo" because we're basically doing a WW2-type setting without the infamous "wake-up call" of WW1 when folks tried to run down tanks with horses. So we have the extra few decades of advancement, but the realization of how needed aircraft and updated weaponry is would not yet have hit everyone. This will mean some things are advanced by comparison (from those extra decades) but others are well behind (because there was no WW1 to kick things off).