Oh my. That's super lame from Toyota. It's really bizarre. Toyota has development resources to build two different frames to have leaf and coil springs and at least 3 axles in rear and IIRC 3 different brake sizes, but can't build a proper wide track suspension for the 3 trims that make up 50% of sales? Very disappointing. And probably drives poorly with the offset wheels.Tacoma track width unfortunately isn't what it seems and is explained here.
I assume that the reason why the lengths are different is simply because pickups, by nature, are pretty modular. Put this here cab with that there bed on this length chassis and you can have several different trucks with only a few different cabs and beds.
It's even more curious why when the tundra oem front suspension lift kit is very comprehensive and reasonably priced. But they won't put in even basic effort on the taco models?

