On the surface I like the idea but imagine in maps like the ones on Stalingrad at what extend you could fortify an objective, especially if you add the increase health ? (but it would depend on the amount of health added, because I do think that sandbags are a too week too, more on this later). Because it would not only protect those inside but completely block entry point on objectives.
An other way to implement better sandbags would be adding a new type of one.
They would be visually different like with the addition of wood logs (or even something specific to a faction and/or a battlefield, like sandbags wall reinforced with the aforementioned wood logs for Moscow and with construction rubbles like bricks or sheetmetal for Stalingrad and Berlin, and just rocks or more sandbags for Normandy and Tunisia), they would be the same length but a bit thicker, they would also be slower and more expensive to build but would need to be hit by multiple direct hits by artillery or tank guns (the number would depend on the type of shell and caliber of the gun).
This would make more open or / natural strategic position like hills more viable to put capture points.
Because places like the last point on Airfield which are completely devoid of any cover after a few minutes and just end up being a grind fest of who is going to be able to throw as many people one the point as soon as possible and the victory will just depend on who will have placed their rally points the closest and which side will have the least AI stuck running into a wall on their way there.
A way to make them in a continuous line like in most RTS would also be good step toward improving sandbags imo, like in Iron Harvest where you orient where the sandbags are going without having to leave gap or stopping construction,the next shape of sandbags wall would just depend where you are aiming around the last sandbag wall built :

Same for barbed wires, or at least being able to put their starting and finishing points (the same way you place AP mines in the Sniper Elite games) and then building with a construction time depending on the length of the fence.
They do get destroyed quite easily, but my main issue is that it seems unreliable, sometime a 75mm HE shell doesn’t seem to be enough, sometime a frag landing 5m away seems to be…
I disagree on that point especially to protect objectives (which are often in buildings).
A few barbed wire on Stalingrad and attacking become way harder.
Yes it would, but Hell let loose also have much bigger maps.
On D-Day if you could build walls of barbed wire (that can only be destroyed by engineers or people with axes) with two of them at those gates one each side of the second central bunker, you could seriously halt either the allies when trying to reach the second or even the first point depending of the configuration of the game, or totally prevent the Axis to reach the first objective if it’s the original first one in the first central bunker.
There is too much ways to make this being abused to absolutely cheese a game.
This a great idea and I love it, however as mentioned before imo it’s not compatible with the impossibility to destroy them except as an engineer, mainly because now axes are going to be way less present than before.
Getting one for free in addition of a weapon at the time of the “random stuff for bronze order” loot boxes was fine, now nobody is going to be happy to have to spend silver orders to get axes just in case someone decide to use their engineer at their full potential and potentially single handedly block the entire enemy team in a few seconds.
However being able to destroy barbed wire in a few hits would be a great mechanic and would allow a bunch of new possibilities for melee weapons.