So you're looking to level two groups of five new accounts, without any connection to the existing accounts you already have?

I'd do a really simple double chain.
And do it twice.
A > B > C
A > D > E
That gets you five bonus LV 80s; two of them (both on A) will become a Lock and a Priest, to give you 5x of each composition.
But you still get a bonus character on A, B, and D that can be anything.

Ideally character transfer a booster, to 'A' from a main account.
And then use 'A' to boost BCDE, first with Priests and then with Locks.

Then you create characters to receive granted levels.
You'll need one LV 2 character on both B & D.
And three LV 2 characters on A.

C grants 39 levels to the level 2 on B.
Which makes them level 41.
C grants another 39 levels to the level 41 on B.
Which makes them level 80.

E does the same as, with D being the recipient.

A needs three characters, at LV 2.
B had two toons boosted (the same as C), so B gives a full level 80 to A.
D had two toons boosted (the same as E), so D gives a full level 80 to A.
Then B & D each received an 80th...
So that character grants levels to A (2nd to 41st) and the other character finishes the process (41st to 80th).



Then repeat the whole process again, but with the other five accounts.

You would ideally want the 'A' account, in both chains to be on one of the main Battle.Nets.
Just so you can transfer the booster, without an additional delay.

The BCDE accounts can be wherever you want, regarding B.Net emails.