My favorite unit to fling about with teleport would be a Burrowed Stone Spirit. Being burrowed, DR/2, and with an MD of 15 it's a safe bet he'll survive until his activation. At that point, anything within 9" of him is getting squashed something fierce. Many a giblet pie has resulted as an aftermath to this behemoth as he wades through the enemy lines. Seriously, I can't think of a better unit to magic into the heart of your enemies forces. . . 'cept maybe the Broodmaster, but that's a different story and faction.
Which brings me to the successful piercer army. It's totally possible, but you have to be creative with troop numbers and size. You can have a very successful just Piercer for your soldiers build, but you will want to take earth elementals and other large gribbly's to smash anything a crossbow bolt won't stick to. Magic and distance between your soldiers will also be key. The only reason I bunch up my O'lord Xbow's is because they get lock shields +1DV and +1MD. FOr piercers, I start them apart and only enlarge the distance. This forces your opponent to also split their forces or waste large portions of points trying to kill 1 or 2 piercers at a time. Here come the large gribbly's. An earth elemental is easily the match of any soldier out there on it's own. DR/2, Burrow, and most importantly the ability to be summoned by a caster means that if you hold your caster back (why wouldn't you) you can summon an earth elemntal when something gets too close to the Piercers.
Your biggest fear with this list is actually less melee and magic and more other ranged units. If something bases a Piercer well that's ok. Shooting into melee isn't a bad thing for Piercers since they fold like tissue in hand to hand anyhow. Plus, you did bring Herryk Aesir right? So that means you get to reroll any failed Dis checks and can usually disengage then take a pop shot at the guy who based you. Ranged is your enemy because most ranged units shoot farther than Xbows. Other than that, remember to focus and let fly your bolty doom upon your foes!
Joshua












