Another very interesting topic. The reality is that creative tension will only be a problem if the basis for decision making is not defined upfront. For example, is engineering driving the bus or is marketing or is product. Everyone will undoubtedly "be on board" in the beginning but the moment disagreements arrive the real game begins. Even if you do the "right things" in terms of using research, and I mean good, solid, clean, data (primary and secondary) you will undoubtedly have those that believe they know the market better.
So upfront define the basis for decision making, including who has final say, and for those really tense moments an escalation path and the circumstances it will be used. I have seen, more than once, where very, very good data is nullified by sr. mgmt based on nothing other than just sheer unwillingness to understand the data. In both cases the ventures collapsed because the products produced had zero market appeal. Shocker.
Do you define what is appealing and the likelihood to purchase or does the market? Lastly I would also throw in the matter of whose money is it? if you are funding the effort personally then by all means do what you want. If you have others money involved then you are obligated to reduce the risk and maximize the chance of success, no?