I do something similar to that. Since all my RAFs are referred from the same account I have my 60 Pally run my groups out and smash up kill quests and then when I get back to the quest giver I log her out, log in a 5th from that account and invite to the group, then turn in quests. I log out the 5th, call the pally back and start on the next set. I can log them out anywhere and just use summon friend to bruing the 5th wherever he is needed since all 4 other accounts are linked and never have to worry about th cd time. I keep gifting lvls to the 5th account to keep the toon up to speed. The only way to do this is with at least 3 accounts though, to keep the lvls even. I don't think it would be effective for long with just 2 accounts.