That is very hard to tell.

As far as I know, and that could have changed or was wrong to begin with, they roll exactly one die for the combat. How that combat looks afterwards is completely cosmetic. Also there was talk about hard cappings of your win chance, so no matter the stats, winning is not guaranteed.

But if this is true, then all stats might be equally important for consistent wins. And this is what you want in ranked challenge. It just might be, that on average, only your sum of stats and stamina counts, but since your opponent constantly changes, you would have no benefit of chance in a an evenly matched game. Reason being, you would not fight this challenge, but boost you girl or change opponent, because you do not want to risk your win streak.

If it were a straightforward exchange of blows (he he) with strength, speed and crits with x2 damage, crit would be useless compared to the product of strength and speed and because you spend exactly the same ressource on all stats. But I highly doubt that it is just like as a melee fight in many rpgs.

That being said, most girls I encounter either have evenly stats or lower tricks. And the booster items for ranked are 10% str 12 sp 14 trick 7% vs and 25% str again . Assuming the higher items to be getting better and better, the devs seem to consider the stats to be equally important, but since the best booster item boosts strength, you get more boost, if this is you highest stat.