Just last night in my Romani campaign, I siege a large stone at Ambrakia from the epiros. I thought it will an easy fight on walls, since the Epeirote Elite Phalanx cannot used their pike on top of the walls. So I used classical hoplital, climb up the wall and engage on the walls with the Elite phalanx. I was amaze when I started lossing more men than the Elite phalanx. I loss a quater of my army fighting in the wall of the city alone.......

I know, I know. I underestimated the phalanx on walls. Now I wan to ask, what makes a good wall sieged unit? Do anyone know any unit that can fight on the walls, lose at little as possible and kill as many as possible? I not looking for the "perfect" unit, just something that can be used on walls.