2 accounts to level alts?

[Blokus]

One of my favorite "powerleveling" methods requires at least 3 accounts (or 2 accounts and a friend). Party 2 or more lowbies together. Put high level warlock on follow but not partied. Tag mob with lowbies. Kill mob with warlock PET but DON'T use any warlock damage spells. Gain FULL XP for kill, split of course between the two lowbies.

[The IT Monkey]

One of my favorite "powerleveling" methods requires at least 3 accounts (or 2 accounts and a friend). Party 2 or more lowbies together. Put high level warlock on follow but not partied. Tag mob with lowbies. Kill mob with warlock PET but DON'T use any warlock damage spells. Gain FULL XP for kill, split of course between the two lowbies.

If this works that is great and am going to have to try it but why does it require 2 lowbies? Why does it require three accounts and not just two?

Couldn't you get the same effect by just having a high level lock (or a hunter would work too wouldn't it?) follow around one lowbie?