Sergeant
need to rethink my concept of a diorama,
Given that vets are often surrounded by non-vets, providing context can sometimes be cruical.
Your idea of "firebase as seen from above" is valid for giving a sense of scale and context--something books, videos, still photographs often don't.
However, both Gino and Bill bring up good points.
At larger scales, the vast emptiness between combat units can be daunting to make a diorama of.
However, there might be a solution. Build a firebase to scale, but in small scale, like, say 1/72 or 1/87 at reduced detail, but with enough detail to suggest the intricacies in real life. Then pick ot one or two (even three) "scenes" from that small-scale dio to detail up in 1/35, where you can get the finicky "bits' to show.
Could stand up the small scale version as a "backdrop" of sorts on the base cabinet.
36" x 24" scales to 261' x 174' (±80 x 50m) at 1/87 scale, so, maybe having to move down to wargaming scale might be needfull.
Such are the dilemma of scale. At 1/300 wargaming scale, a 4km tank versus tank display would need to be 13m wide (this is why naval wargaming uses 1/1250scale and needs gymnasium floors--30,000yards is 72' at 1/1250, so scale distances are often halved for play purposes).
At least that's my 2¢. I'll admit to being an outlier, I find fewer vehicls in dios are more realistic--but, I also spent time getting people to stop bunching up on my beach, as the work was hard enough without drawing fire.