Forecasts are forecasts. I wouldn't base my first innings score off a forecast, on day 1 of 5. Getting way ahead of ourselves there. Just do the basics, set a score - we'd already batted aggressively and skewed the game towards a result, why go to such artificial lengths to say you're aggressive. That's just vanity, there is a huge database of history that says strong first innings batting wins games and instead of using that we decide to go off piste.
Besides why equate declaring with more chance of winning? Not neccessarily, runs scored plays a huge part, not just the time to take wickets. Time comes into play as the game progresses not on day 1. The most crucial thing to me is we didn't declare with Jimmy Anderson stood there blocking it up and doing nothing, that would have been more justified because then you can say the opportunity to bowl is better than watching Anderson block. We declared moments after Root just punted their spinner for a couple of big 6s. So by declaring you also have an opportunity cost that says Root was set and could have been extremely efficient in strengthening our position there.
Wasn't a masterstroke, it was just bad. Bad in theory and unfortunately for us it was also bad in practice.