Sgt Wilson was a combination of upper-middle class gent fallen on hard times and at the same time Everyman (that is a
weird combo, now I think of it). He's the one who made sense as you watched Dad's Army -- where everyone else was a caricature of Bombast, Officiousness, Senility, Milksop, Soldier Reliving Old Battles, Spiv etc, yet Wilson barely had enough nous / basic energy to make an impact on his world.
It's a good description of Jason.
ETA: TV used to be so much better than it is now