User blog comment:ClariS/The Ideal ARAM Team/@comment-9713132-20130506120920

Generally speaking your 'poke' team is countered by a team that can go all in and follow up with superb nuking or combo bursts, or raw sustained DPS. An initiate by Malphite, followed up by some position-wrecks like Janna, Orianna or Gragas can screw up your team because you're all over the place and there no longer is a front-line. Your squishies will inevitably get massacred and because your team relies on poke to win, you'll probably lose that teamfight and see them take down an objective or to.

That's really vague, doesn't apply to all situations and I could be wrong, but my general thoughts.