you could try padding putting a bit of greenstuff in their shoulder joints to make them wider, and put them on a double height base which is what I did to make my Termies more impressive. also, adding capes and cloaks really helps to make them more bulky.
speaking of height, for my chaplain on bike I put him on a tripple height base, and added building sprew stuff to his bike to make it bigger
speaking of height, for my chaplain on bike I put him on a tripple height base, and added building sprew stuff to his bike to make it bigger