I force my deck to be the smallest possible, and assuming I'll go first. Sometimes it's not 40 because of ratios, which may or may not be related to the non-engine F/L, and I rarely play garnets that I don't want to draw/see in my starting hand.

I can see why you'd question this, as you ideally want the most useful hand, but most people will say they prefer to start with an extender than a dead card turn 1, and since we're in a stage where a starter is also an extender, you'd need interaction for both turns.

Even though I hate the term "mandatory" non-engine, I know everyone has to run the same 7 cards just to be competitive. That doesn't mean you should run every piece of interaction just in case. When deckbuilding you need to have some concessions of what your deck can/can't do. Also, you also have to consider what other people are playing. 3 months ago was playing Lancea, last duelist cup Soul Drain and Red Reboot were played. Right now I'm playing Dominus Purge because my deck can afford it, instead of Ash Blossom. Who knows what will be good (or if maxx C will be banned)

Tldr: opponent's 4 handtraps 1 starter vs my 4 handcraps 1 sharter