The conventional approach to dealing with a situation whereby the client wants all 3 is to offer them all 3, but to make sure that you don't actually commit to that in writing. So make sure they go with your standard terms and conditions - no milestone-based deliverables or anything. Then, rotate the team frequently and get everyone talking to everyone so that you completely break down any traceable points of accountability. Or, accept internally that your unstated plan will be to do 80% of the job, bill 80% of the fees, then sort of drift away from it and leave the other 20% on the table. It's not just clients that can cherry-pick, you know! At least, this is what I see many other firms of consultants doing... I don't condone it, but it seems to work for them (sadly).