You’re kind of rambling around here. I have never heard anyone say 1000lb. squatters were fast. What some have said is Olympic lifters, and some powerlifters if they include explosive movements, can be very explosive, i.e. jump and start well. Shotputters are a classic example of a very large, very strong, very powerful athlete that usually forms a base of strength on powerlifting, then compliments that with explosive lifting and plyometric training. Many of the top standing broadjumps are owned by shotputters. They are extremely explosive and very powerful, but would not be as explosive as they are at their size without the weights. Football lineman could get along fine training like a shotputter. They won’t run fast 40 times, but they will put you on your butt on the line of scrimmage.
As Charlie has stated numerous times, work many spots on the force-velocity curve for maximum gains.