(deftype tile-designator () '(or symbol (cons symbol (cons (integer 1) null))))

(defmethod shared-initialize :around
    ((army army) slots &key name hq-tiles tiles tile-count)
  (check-type name symbol)
  (check-type tile-count (integer 1))
  (check-type hq-tiles list)
  (loop for cons on hq-tiles do (check-type (car cons) tile-designator))
  (check-type tiles list)
  (loop for cons on tiles do (check-type (car cons) tile-designator))
  (call-next-method army slots :name name :tile-count tile-count
                               :hq-tiles hq-tiles :tiles tiles))