You misunderstood what he was saying perhaps. (just realized you caught it yourself, reading the whole post 4tehwin Jheusse)

The maximum number of grantable levels a character can generate is 29 (at levels 3,5,7,9,11,13,15,17,19,21,23,25,27,29,31,33,35,37, 39,41,43,45,47,49, 51, 53,55,57,59)

The maximum number of levels a character can accept via granting is 59 (no I'm not typing them all out, 1-60 )

Either that or you understood him correctly and he's wrong for one reason or another.

With the way you have them set up, the idea of swapping the vets to boost for the "other team" will work very well. Running two teams to 60 on each group you'll generate 8*29= 232 levels available to grant to each veteran account. That's almost 4 free L 60s on each veteran account. And in general you want to avoid using those gift levels to grant low levels like 1-10 or 1-30, it's a waste of the resource, which makes those 232 levels go even further.

TLDR version, you're gonna have a ton of levels to grant and accept, since you obviousl yhave the money to afford 10 accounts and the relevant hardware, I think you're going to end up creating a bunch of additional 60s on the veteran accounts and account transfer them off to other accounts to make more room to level more toons with the gifting.