Same here. The hard line to walk is presenting a front to upper management so you dont across as a non-beleiver to them. Big companies have systems in place to catch the non-beleivers. Sometimes I do wonder if we are in the corporate version of the man from the high castle!
Honestly, I don't front to upper management either. I ask what the strategy they want to try is and if they ask me if I think the strategy is correct or not I give my honest answer. If they don't get honest feedback from us then why would we think they could make wise decisions?