Yes, the two chains is ideal for boosting.

For each link in the chain, you need to level/boost two characters for the cascade granting levels to add up to full characters.
A > B... level two toons on B, and B can give a full toon to A.
A > B > C... level four toons, and the levels C gives to B, B can use to grant a full toon to A.



I recommend this one:
A > B > C
A > D > E

C/E just get what you boosted.
But you get additional toons on A/B/D.
And A actually ends up with as many toons as B/D, without needing to level any toons on A.
Or you can level (a x5 group) for the first set and then use A's toon to boost later teams.
Also, if you're tempted to play on a server with other boxers, you could transfer one toon (the A character) with wealth/heirlooms/etc and boost on a brand new server.