J.S.
First - congrats on breastfeeding twins! Even tho you need to supplement with formula here and there you are giving them such a wonderful gift with the nursing!
Now on to teething...teething is one of those things that really does vary from one kid to another. I have 3 boys - each one started teething around 2-3 months of age. First got his first tooth in at 10 months...second son - 3 months...3rd son - 6 months. Lots of variation within the family...interestingly enough, when they got their teeth in also played a part in how old they were when they lost their first tooth!
So, teething discomfort is one of those things that you have seen can vary from day to day. Hyland's teething tablets/gel is a great help. I prefer baby ibuprofen over tylenol as it is an anti-inflammatory and seems to be a bit more effective at relieving the discomfort longer (anecdotal experience). I generally suggest to my mommies whose babies are having some discomfort to only give the ibuprofen at night time and use other means during the day to ease babies discomfort. I love the use of a big fat carrot to chew on... :) I advise against frozen toys or foods the baby must hold because it will make their poor little fingers VERY cold!
Now for the waking...NORMAL! But it seems you already have an idea that this might be the case. And you are correct that the waking varies from child to child. My three boys all had drastically different sleeping patterns. Sometimes they would sleep great and other times they would not. But I find that is the case with most humans in general regardless of age. :) As long as you are OK then I would simply 'go with the flow'. :) Wonderfully you are not a fan of the cry it out method - neither am I. I had never termed it a form child abuse but I believe you are VERY correct - it is. And I do suggest to my clients that the CIO method is one of the main reasons our society has so many abandonment and trust issues... And, in my personal opinion, separating them may or may not help. I don't personally like that idea and it certainly doesn't go along with co-sleeping unless you put on on dad's side and one on yours with you and dad sleeping in the middle...then you have to deal with the possibility of baby rolling off the bed if you aren't already using bed rails to prevent that. :) My recommendation would be continue to co-sleep and continue to give your babies that gift...because it is a wonderful gift you are giving them. :)
For your situation I think the best thing to focus on that will possibly help the sleep would be the teething. Find ways to make them more comfy at night.
If you are in the Sacramento area and would like to talk in person to other moms who are going through this too we'd love to have a twin mommy at our mom's group. :) Go to www.breastfeedingnetwork.net and find the Mom's Group page. It will give you all the info you need. It is a wonderful group of ladies...
Good luck and keep up the great work you are already doing...
Warmly,
J. Simpson, IBCLC, CIIM