It would make sense if it's a real truck frame and the bus cab was fitted to it.
Say the cab of a truck was smashed and the bus cab bolted onto the frame.
Why cut up a school bus body and add the dually axle gear?
But, I have seen guys miss match car/truck parts that made sense to them and not me.
2013 24RKSWE (27ft TT) Cougar 1/2 ton series SOLD 10-2021
2013 Ford F350 4x4 CC 6.7 engine, 8 ft bed, 3.55 rear end, lariat package
Retired from Oregon State Police in 2011 than worked another 9.5 years as a small town traffic cop:
As of 05-2020, I am all done with 39 years total police work. No more uniforms for me.