Everything you said was factual I was just trying to reinforce that it will be far more difficult and expensive that it's worth. I have an E-maxx with the dual 21t motors and it may be the most dissapointing vehicle I ever bought. Sounds like it's going to fall apart everytime I hit the brake.
I have owned 3 different emaxx's
I love the size, and the power is pretty good if you use a pair of 2s lipo batts.
But the plastic bulkheads, and slider shafts were always an issue.
When it came down to it tho, I just dont like running a truck that requires 2 batteries.
But to the OP, I think you get the point, a twin motor volcano will be a pain to build and wont perform as well as a brushless system.