Mat strength is not the same static strength used while lifting.
That’s why often times someone that has experienced lifting weights expects their strength to transfer easily to the mats, and they are wrong.
In my opinion lifting weights for BJJ and MMA is best to do for injury prevention, true man to man strength comes from years of moving bodies and controlling your own body.
I’m 39 years old, 225-230 lbs, and can move like a man half my weight. That’s because Jiu-Jitsu my friends.