City of Angels T2013......

[StainlessSteelCynic]

Not necessarily weak, I'd say that while it could be called unlikely it's not implausible.
A possible scenario for how all that gear game to be in the USA would be the one from the computer game World In Conflict. In that game, Soviet military forces were hidden on container and RORO ships with much their gear packed into sea containers. They waited until the bulk of their "civilian" fleet was in place and then started offloading vehicles and troops onto the docks under the cover of attack helicopters. Once they established their beachhead they sent out battlegroups to start the invasion proper.

So taking that a step further, why unload the gear from the shipping containers to load it into military trucks for distribution when you could hitch a couple of container trailers together and make use of the good road network in the US. That also keeps the military trucks free for troops and immediately needed supplies.

So then, a modestly guarded convoy of container trucks is travelling down some back road and gets hit by a USAF airstrike, there's going to be plenty of ruined equipment but the odds of some surviving in a usable state is pretty good too... and then the PCs are sent in to do a battle damage assessment because they just happen to be nearby (or maybe they came upon the aftermath while doing something else).