Hah, you may be right about that.
I was so certain that CC attacks could be targeted any way you liked, but reading the BRB again they actully say that "If a model is touching enemies with different characteristic profiles, it can choose which one to attack"
So by omission I guess you can't divide between rank-and-file, just as you said.
With that in mind, does this look like a correct sequence:
1) Champion attacks. X wounds caused.
2) The X wounds kills Ogres (from the back rank of course), the remainder leaves an Ogre with (for example) 2 wounds remaining. I now roll the multiple wounds on this final strike and get a 1, so the Ogre still has 1 wound left.
3) My rank-and-file attack, and their first wound kills the previous Ogre.
This way I don't really have to keep track of special wound counters in the front rank. But I know a lot of other people have been talking about rolling a dice separately for each wound caused (as you should do according to the rules, roll multiple hits for each hit). This way feels a bit weak, and I feel like I'm missing something.
Maybe this is more correct:
1) The Champion attacks. X unmodified wounds caused. (Let's say at least 3 this time)
2) I apply the first hit to the Ogre, and then roll multiple wounds. (I roll 6 wounds, meaning I kill the Ogre and lose the 3 remaining wounds).
3) I apply the second hit, and again roll multiple wounds. (This time I scored a 2, leaving a 1 W Ogre)
4) I apply the third hit, and roll for multiple wounds. (I roll 5 wounds, meaning 4 are wasted and the 1W Ogre dies)
5) I apply the remaining hit(s) in the same way
You know, now that I wrote it out this second method really seems like the way to go. It lets me both roll for every wound caused, and still punishes me with wasting wounds. And it's really simple.