I'm running 5 accounts.
And have heirlooms as follows:

A: None.
B: Cloth Shoulders, Leather Chest + Shoulders.
C: Cloth Chest + Shoulders, Leather Chest + Shoulders.
D: Leather Chest + Shoulders.
E: None

I go for Stonekeeper Shards for shoulders if at all possible.
To save the badges for more useful things.
The chest has to be badges, the shoulder can be shards or badges.

I'm going with cloth -- caster stats.
And leather -- melee stats.
And that will be it; if I ever level ret pallies, they'll use the leather.

I'm in the slow process of banging out heroics.
If I enjoyed dungeons more, it would likely be a bit faster.