Well, no, it was my own method. As it turned out, an inefficient one =] And I'm glad it wasn't the best one. But anyway, the target of this thread is to find the cheapest way to get those bonuses.
You and 112000 made a good point: rotation (or is it better to say "reduction the number"?) of players is the key to spend less condition. 8 * 27% = 216% total CL was my best.
112000 has reduced this to 4 * 27% + 4 * 18% = 180%, and this is current record. I've just tested it, it works. Clever!