I'm still wondering how their combat organization related to their construction organization. Were Seabees assigned to squads and teams at random?
From squad level on up, they are organised primarily as construction crews that can be assigned to get work done. Each battalion developed it's own 'personality' of expertise — airfield, road, base, dock, etc. construction and needed workers grouped to accomplish their whole project quickly. Although depending on the immediate needs, they might be called on to do anything.
Including being called on to do anything in combat. This crane operator did duty digging rapid emplacements for a 105mm howitzer, and later excavating Japanese caves when not employed working on the airfield at Iwo Jima!
https://www.navytimes.com/news/your-navy/2019/02/22/a-seabee-on-iwo-jima-the-men-who-drove-cranes-and-cats-also-served/ Specialists were frequently shifted between battalions where any particular experience would be most needed. Skimming through battalion logs, Lt.s and Carp.s (Carpenter's Mate rating, usually given to skilled foremen) are the ones who get bounced where needed.
For a skirmish game, I like my squads and platoons to be historical, but am happy going cinematic with a heavy proportion of support so I can build and play with the toys. For more balanced representation, and building and playing with all the toys, I prefer 1 vehicle/stand = 1 platoon and play Blitzkrieg Commander.