Perhaps, but there's a reason that anyone in supply chain or logistics tries to standardize on the fewest SKUs as possible. Planes are a special case because weight _really_ matters and thus it's worth the loss of standardization.
Imagine the nightmare of what happens when a driver grabs the wrong bus and is several miles along their route before they notice. Do they return to the school? Do they get as many kids as they can before they run out of charge while a dispatcher furiously tries to coordinate a place within range but still further along the route to send a whole new bus to switch the kids onto? What happens when the driver who's bus got taken drives off in ANOTHER driver's bus, perhaps with the same results cascading onwards?
Currently you have to balance drivers, bus capacity, and bus breakdowns/availability, but you don't have to manage bus charge because the gas range is large enough and the driver can quickly top up if needed. Adding another dimension of complexity into it likely isn't worth it compared to the cost of having a somewhat larger battery.
Imagine the nightmare of what happens when a driver grabs the wrong bus and is several miles along their route before they notice. Do they return to the school? Do they get as many kids as they can before they run out of charge while a dispatcher furiously tries to coordinate a place within range but still further along the route to send a whole new bus to switch the kids onto? What happens when the driver who's bus got taken drives off in ANOTHER driver's bus, perhaps with the same results cascading onwards?
Currently you have to balance drivers, bus capacity, and bus breakdowns/availability, but you don't have to manage bus charge because the gas range is large enough and the driver can quickly top up if needed. Adding another dimension of complexity into it likely isn't worth it compared to the cost of having a somewhat larger battery.