If you'll be boosting with A all the time, I wouldn't include it in the linking at all.

Go with existing account B, and link from there to any of the new accounts. Daisy chain them, so B to C, C to D, D to E... for cascade granted levels.

Use non-linked Account A to boost your B, C, D, E etc accounts, when they're (the lowbies) are grouped together. A will be in the group, but its not linked at all.

As an aside, you mentioned your account and your wife's account. If they're not in the same name, I wouldn't use multiple accounts at once. We get a lot of attention and are reported frequently. You want the account names to be the same across your whole team. The costs as far as subscriptions go is minimal, if you pay for a month on a new account the existing account receives a month free. When your done, you can toon transfer to the accounts you're keeping.