What they teach and what can actually be done are 2 different animals. Simple school teaching for newbies. Vs. real world experience.
34 on tandems yes. Spreads can go 40. Add axles and you can go higher. Newer trucks can scale 13k on steers.
Newbies are taught the basics. As that's the whole operation. No reason to teach more as they don't haul more. Just a basic 5 axle setup with reefer trailer. 34 on tandems. 80 gross. There's much more to learn but that comes with experience and different operations.
Now, if the company keeps you to 12 on the steers. Then i guess that's their decision. But technically you can scale up to 13 provided the steer axle is rated.
Balance would be prefered but also UNrealistic with most loads outside of dedicated van shippers. And liquid shippers. If a guy is picky. I guess he could spend his time pissing shippers off reloading to make him happy with balance. And balance would only apply to fully grossed loads. There are lotsa loads that are nowhere near gross. IN the summertime. No big deal. In the winter time. YOu want weight on the drives for traction if needed.
In the end. All one cares about is legal axles and bridge. When it comes to Cali. They don't care about your weight balance. They only care about your bridge. 40 bridge is more important then balanced loads. But if you're fully grossed. Then obviously you need that weight balanced.
Different loads. Different situations, Different scenarios. Different operations.
Reefer loads probably won't encounter much different, though.
BTW. I have a drop axle on truck and drop axle on trailer. 7 axles total. I'm usually 43 on the 3 axles each and almost 13 on the steers. That puts me at 99 gross. I pull a 52 foot tanker.