In a way, it might be the other way around, since you use more weight - there's a bigger chance that one of the smaller muscles gets overwhelmed and messes up your form/compromises stability.
My train of thought was more weight = quicker gains, like in deadlifting. Or compare benching to shoulder pressing.
Well, it's hard to pinpoint the ratio of weight/gains, since there are other parameters at work. Maybe you don't hit the same depth all the time, maybe you're limited by this or that muscle that adapts over time when your protagonists don't etc. Who knows? My brain is too destroyed to think about it.