The pic above of is an Assault Breacher Vehicle. It arrived with great acclaim and was hailed as an example of out of the box thinking, frugality and a can do spirit.
All that is true but its also a remarkably specialized vehicle. It can best be described as an enabler for the Maneuver Force. It provides protected mine clearing over all terrain with either a highly effective mine plow or line charges. Blasting fortifications is not in its job description. Building them isn't either.
The Kodiak gets closer to the mark of a real dual role vehicle and the different attachments that can added to the "extended" arm make it beyond valuable.
Both vehicles serve the needs of the forces that they're attached to. The Marine Corps developed the Assault Breacher Vehicle and the idea is that its to keep an assault moving...the idea of establishing a defense and fighting from it are actually a role given to the attached Engineer Support Battalions.
The US Army has bought a few ABVs with the idea of them being attached to heavy brigades. These are hyper assault units (the Army won't describe them as such but look at the organization) with defense being a second --- a distant second task.
The Kodiak like I said above is more the dual role vehicle. Its outfitted to function in the assault using the same plows as the ABV and with the attached arm can be used to build field fortifications.
A quick view then gives one the image that the US is focusing on Sapper type vehicles while the Germans in particular (and many of their European counterparts) are focusing on multi-function vehicles. It wasn't suppose to be that way and the Grizzly was suppose to give US Army Combat Engineers a true multi-purpose vehicle capable in the offense and defense. Congress thought better of the idea and canceled the program.
One vehicle that needs to be brought into this discussion in the assault role (Sapper as I'll now call it) is the D9 Bulldozer. What I find fascinating is that the Israelis were once accused of doing all kinds of horrible things with it. Then suddenly it was purchased and used by the US Army and others without debate.
The final vehicle on this list is one that I personally consider a failure. The Stryker based Engineer Vehicle. Its basically just a Stryker with a mine plow. I love the idea of a Family of Vehicles but this is as big a failure as the Mobile Gun System.
Other combat engineer vehicles are in my opinion variations on commercial vehicles. A few vehicles were designed to be Airborne, high speed, amphibious etc...They aren't widely used. It seems like a true multi-function (across all roles) combat engineer vehicle still evades the force.