Question: What other books or stories are out there like The Defense of Duffer's Drift? Stories that can help me to understand defending our home and farm. I've read the ranger's handbook, but it's really not about static defenses. I don't want to read about building huge sandbag fortifications. I just want to have some ideas to think through fluid situations
The reason it is difficult to find a book/account akin to "Duffer's Drift" is because of evolution in warfare. With artillery, it is dangerous to stay in a fixed position. In the age of bows and catapults, castles are still viable as semi-permanent fighting positions. With the proliferation of gunpowder, all fighting positions became temporary. Therefore, your scenario/premise is faulty to begin with: Any defensive works (trenches, et al) is only a means to gain time, time to evacuate your dependents and stores.
If you want stories on fighting from trenches, working on trenches, books on Vietnam and WW1 are probably your best bet. (Korea has plenty of positional warfare, but most accounts are in official history forms.) McDonough's Platoon Leader is a good book on being in combat, setting up a Platoon Patrol Base, and leading patrols. Command Legacy is also a great starter/complement to Ranger Handbook and FM 7-8 on how to set up a defense.
For more thoughts on defending a homestead, check out the Infantry tag. Below is a short primer.
Contrary to popular misconception, WW1 was not a triumph of machineguns and trenches. More properly, WW1 was the triumph of the railroad, the counter-attack, and artillery. The allies and Germans usually succeeded in breaching the trench/defensive line. However, they were never able to exploit the breach. Artillery meant that it was almost impossible to mass your reserves close enough to exploit the breach. Even if you did breach, the railroad was always able to bring in the defense's strategic reserve and set up a defensive line to contain your exploitation and counter-attack. Mass conscription meant that there was always a strategic/operational reserve.
The Blitzkrieg, more than anything else, was the tactic to exploit a breach made by the infantry. Rommel's WW1 memoir, Infantry Attacks, is a classic on the German stormtrooper tactics for breaching trenches. On Infantry is another classic that discusses infantry principles.
Therefore, as Command Legacy says, your defense consists of 3 things: Combat Patrols, Fighting Positions, and the Counter-Attack Reserve. Combat patrols are fairly obvious, you patrol to disrupt enemy reconnaissance, provide advance warning, and make the enemy to commit prematurely. The combat patrol is what you use to take out enemy snipers, and helps you pincer during your counter-attack. You use your Reserves and stragglers to ambush the enemy when they breach your defense, and to counter-attack when he culminates in his exploitation.
For fighting positions, you try to set up 3 per: Primary, Secondary, and Tertiary. When the enemy makes a hole in your defense, you do not try to plug it immediately. Instead, your defenders, who are now in untenable Primary positions, withdraws to their 2ndary in an orderly fashion, while your Reserve sets up an ambush. When the enemy now comes through that beautiful hole they just made, you cut them down, repel. Then while the enemy is re-organizing, your defenders go back to their Primary positions, and you plug that hole then.
If the enemy is overrunning your defense, and you have to continue holding your position (ie, evac is not complete), then that's when you fall back to Tertiary (ie, squad bunker/safe room). From your Tertiary position, you wait as the enemy rushes past you, then shoots them from behind. Hopefully you have a Reserve/Reinforcements coming to rescue you, but if the numbers are against you, then this is either where you fight to die or where you fight to breakout. In Vietnam, that's when they call in the artillery on their own positions. In your case, you might blow up your own house when the attackers are all On The Objective.
Therefore, obviously, your Primary positions may be quite a distance away from your homestead. If they are sieging your house, then it's a very bad situation. You want to keep the defense mobile so you can trade space for time. In WW1, German infantry took to using allied shell craters as their 2ndary positions, using a limited form of mobile defense.
As you can see, a proper defense takes a lot of people. If you are less than platoon-size, then you should commit to staying mobile. Not to say you shouldn't be farming, but don't get married to your land unless you're willing to stake your lives on it. You can always come back to the land later (root crops), but you can't exactly replace your family.