I think you should always force*. And let me explain:

You can make some variations, depending on what champions you get (Shen or GP, Fiora or Camille, Zed or Pyke), but the core strat should be planned really early, when you get your first items (most of the time, after Krugs), because the power of a strat relies on its items.

If you don't plan it, chances are your early game is going to be powerful (because you take every 2* you can instead of forced ones) but at level 7+ you're going to be a little bit weaker than refined forced strats that reach their powerspike there.

Yeah, your comp is going to be way more adaptable, you're going to have a lot of synergies, but that's not enough at level 8-9. you need 6 nobles, 4brawler+3void+3sorcerer or something like that if you want to win.

*I'm not talking about Jinx or Draven, which I would always take a pair if offered and add an extra Hextech/Imperial for them.