Dad's Army was always quite inconsistent its output. Some episodes were very clever while being absurdist, some were just silly farce. This is one of the latter.
From the moment the WIlson and Pike decide to sabotage Mainwaring's boots you know this is more caper than clever comedy. Once the platoon, indepedent of Wilson and Pike, decide to do the same you can see how this is going to progress.
From that point it is quite predictable. There's some decent hijnks in the shoe store but that's about it.
To make matters worse, the ending is anticlimactic. Instead of some great comeuppance the episode just ends, without any real conclusion.
It's all fairly low-key and beneath the usual Dad's Army standard.