The big difference is that you need rigid tubing, colloquially known as "hard suction" hose to draft from a static source. Typically soft-walled hose would collapse if you applied suction to it. At least in the US, most engines carry hard suction tubing, but I believe some urban engines may forgo it, opting to use that space for something they use more often. And even if they do have it, the engineers may not have a lot of experience setting up a drafting operation.