I personally would not recommend doing just one team.

I'd RAF link five accounts.
If at all possible, have a booster on account A.
Someone at higher levels, who can take and deal AoE damage.

Link the accounts:
A > B > C
A > D > E

Use A to boost four toons on BCDE.
Which then allows C/E to give two toons to B/D.
And B/D each give two toons to A.
Then B/D each give another toon to A, because of granted levels received from C/E.
For a total of:
A: 6x Characters (plus the Booster)
B/D: 6x Characters
C/E: 4x Characters

Then repeat the process, with the second set of five accounts.
Probably transfering the same booster to the new account A.
With ten accounts, you'll need a minimum of two Battle.Net accounts.
Just make sure the "A" account in both sets is on the same B.Net email, so you can instantly transfer the toon without wait times.

Having four combinations will be superior because that is more options.
You never know what will be fun to play down the road.
Or what will be changed/nerfed and become less fun to play.
You have a few aspects to consider, and can specialize teams for each... BG/World PvP/City Raids, Arena PvP, Instances/Heroics/Raids, Questing/Farming/Tradeskills/Gold.