Mount
(
: Attach or unattach a creature to this as a sorcery. Mounted creatures are attacking if this is attacking, and blocking or blocked by a creature if this is. Combat damage must be assigned to this before mounted creatures.)
Any number of creatures can mount Armoured Train.
See Challenge # 141.
My so-far favourite Mount mechanic from Fine Charger. I think it avoids almost all of the problems, and is reasonably intuitive, but is wordy and completely untested.