Bad assumption -- a packed bus is nowhere near 112 passengers. It's somewhere between 60 & 80, depending on how packed.Assuming a packed bus holds 112 passengers and the gondolas are inefficiently filled with 6 people, then that is the equivalent of one bus every 4 and a half minutes.
Unless you're talking about the 60' artics, of which Disney has only 12 and last I heard no plans to acquire any more.