An observation I have made from experience is that sometimes this is due to squat depth being shallow. You cant fudge deadlift performance, but squat depth is the most varied lift of all.
If your unsure about depth, squat to a milk crate, thats 30cm high, close enough to parallel for every lifter.
we use a 29cm box, the gym record is 200kg, thats with a dead stop on the box.
Americans claim for every inch you squat high, thats 40lbs extra weight you can squat. Not sure how they came up with this, its a powerlifting measurement.
Check your depth before you compare. The reason I say this is I had a 17yo boy pull 130kg first time he ever attempted the lift, he is nowhere near a 100kg squat.