I prefer take the same approach taken by the US Army when they studied the pros and cons of either issuing gun-shields to machine-gun crews, or just fielding better and more body-armor.

[sub]footnote: As this study occurred during the Vietnam war, many of the casualties [i]came from patrols getting blindsided[/i] with snipers, land-mines (grenades), and artillery (grenades). One required the operator to have a pretty good idea of where their enemy was at all times while the other did not, [i]and since both items weighed about the same...[/i]
-You may have ran across a "for-shields" idea of "combat reform"... That's the lil tidbit Sparks left out of his essay.[/sub]

[i]Anyways...[/i]

Placing anything that constituted "protection" between yourself and the perceived threat is commonplace.
-The various attempts to up-armor the Sherman, [url=https://upload.wikimedia.org/wikipedia/commons/f/f8/Sherman_Firefly_9-08-2008_15-05-43.JPG]either just the turret-front[/url] or the hull-front ([url=http://www.kiwimodeller.com/~kmodel/media/kunena/attachments/116/m4-skirts-aa.jpg]steel[/url] or [url=https://s-media-cache-ak0.pinimg.com/736x/0d/32/86/0d3286a07227ff04a718b771e8642ca9.jpg]sandbags[/url]), or logs alongside (steel plates covering the ammo-bins was the first 'official' upgrades, [i]but was scrapped since the bulges provided aim-points for German gunners[/i]*) have been made.

Patton was notoriously against such practices.
*Later improvements were wet ammo-racks, and larger and thicker gun-mantlets and dedicated tank-vs-tank training from hull-down positions, plus the adoption of the 76mm High-velocity gun and getting the M36 Jackson into the field in case such measures faltered.