Consider a fresh batch of RAF.

Take a booster, whatever the best toon is...
Likely your highest level toon, especially if they're a tank type.
Feral Druid, Frost Death Knight, Paladin in particular.

Transfer that toon, to the server of choice.
Send your heirlooms with the toon, if you have any.
Send as much gold as you're allowed to take.
If you have more gold, buy items you can sell on the destination realm, especially if they're cheaper on the origin realm.

Boost with two RAF chains:
A > B > C
A > D > E

You end up with at least one character on A, for every team you boost.
B and D, each grant half a character to A... assuming A levels to 2nd (39x2 = 78 granted levels).

Because you have two links in each RAF chain, if you want the cascading of granted levels to add up to full toons (boosting from 2nd, not 1st...)...
You need to boost sets of four toons, as in boost 4 or boost 8, etc.
But it's probably good enough, that if you boost five classes on BCDE, A gets at least those five classes via granted levels.

BC and DE have valid RAF chains, even if A is a lot higher and more than 4 levels higher than B/D.