Even Vetinari is in love with the magic of the railways. He indulges his passion as a humble stoker, deceiving even Moist von Lipwig, gets to fight in the short...whoops, not temporally prolonged, that is... little ... err, that is, not many people get killed or injured.... civil war that restores Low King Rhys Rhysson, or at least a successor who is close to him, to power over the Dwarfs. It also gets him an unparalleled view of events at the sharp end, earns him a favour from the new Low Monarch, puts him near Margolotta, and allows him to refresh old skills taught at the Assassins' Guild school. In the meantime, Charlie, guided by Rufus Drumknott, holds the fort in Ankh-Morpork.
According to tvtropes, and [would they lie], the humble shovel is the most versatile tool in a soldier's armoury. you can hit people with it, use it as a makeshift frying pan for your bacon and eggs, put an edge on it and use it as a cleaving weapon/axe, and if all else fails you can even dig trenches with it.
Also, some schools of Fan Fiction explore the idea that young Assassins these days are taught Unorthodox Combat Skills by suitably trained people, which include imaginative uses for whatever you can lay your hands on in a hurry. Art imitate unofficial art?