FlyerTalk Evangelist
Join Date: Aug 2011
Location: Barcelona, London, on a plane
Programs: BA Silver, TK E+, AA PP, Hyatt Globalist, Marriott LT Plat, Hilton Diamond
Posts: 13,033
Since your ultimate desire is to have return tickets booked for 45K each, you'll need to book 2 tickets out of the 120k account and the other two tickets individually out of the other accounts.
Even if you wanted to book one-ways, you can't top up to 22.5K out of two different accounts to book one reward. Each account must spend the miles for at least one leg of the ticket (i.e. 22.5K) So you can't get 3 one-ways @ 22.5K each out of 60K or 50K.