Reddit mentions of Battle Cry of Freedom: The Civil War Era (Oxford History of the United States Book 6)

The capital of the Confederacy would have been substantially more defensible by land, but it is worth remembering that ultimately the fall of Richmond was more a symptom of the Confederacy's loss of the war than its cause, which came as a result of the Union's systematic encirclement, isolation, and division of the economy, followed by pinning its main army down by the use of superior numbers. As a result, I'd argue that keeping the capital in Montgomery doesn't prolong the war.

It's an interesting counterfactual, though, because there's not a lot of reasons to stick with Montgomery besides defensiveness. Richmond was chosen as the capital of the Confederacy for a number of reasons, both political and economic. You correctly point out that Alabama possesses industrial capacity today, but the iron and manufacturing center of Birmingham didn't develop until after the war. In fact, in 1861, the South possessed precious little industry at all. Richmond was one of these, and one of the mightiest, thanks to one key advantage: the falls of the James. Since the city was built directly on the Fall Line, unlike most of its neighbors to the north and south which were typically built just below the Fall Line for easy access to navigable water (for example, Fredericksburg, Alexandria, and Petersburg), it had easy access to water power simply by exploiting the natural ~100' drop in elevation. This provided a fertile environment for businesses such as Tredegar Ironworks (the third-largest in America and the largest in the South, which produced half of the artillery used by the Confederacy by itself) and the Gallego Flour Mills (the largest of its kind in the world). In fact, according to an estimate by James McPherson, Virginia's industrial capacity was "nearly as great as that of the seven original Confederate states combined," and was focused in areas the South sorely needed: ordnance, cannon, and manufactured comestibles. Richmond was also one of the largest rail hubs in the South, with Atlanta close behind and developing into a more important one following the war.

Without all of that protected by the Confederacy with all of the energy and money that desperate self-preservation can provide, you run the risk that Virginia falls more swiftly, and with it the South. The Confederates knew this, and it factored into their decision-making. Better to risk attack from the North than to lose the only ironworks large enough to supply the army they knew they would need. Ultimately, I think their decision was correct. It just wasn't enough.

I don't think my argument is the be all end all, but if I had to suggest reading on the subject, I would say read Battle Cry of Freedom:

https://www.amazon.com/dp/B002NXOQLQ/

I think a few things have recently been debunked, but it's still pretty much the go to for what I would call an even handed approach. Also, probably my favorite all time non-fiction book.