I have a 1995 Acura legend and it was a project car to replace all suspension parts, bushings etc. basically I started with the rear suspension, replaced everything there including struts and bushings and then moved to the front. Due to complications it took us nearly 2 years to complete the front suspension, in which the rears were on jack stands to hold the pressure off the struts. Now (after an alignment) the rears are like 4 inches lower than the front which have oem springs, and there isn’t body roll left and right, the whole rear bounces from left to right after a bump is hit. The control arms and tie rods were also replaced so they couldn’t be bent, so what’s the problem?
The rear suspension fixings should only be finally tightened when the weight was on the wheels...
If you tightened them with the suspension fully extended then you « pre-load » all the bushes causing a different suspension response.
You could try releasing the bolts - wobbling the car side to side and then retightening the bolts / nuts.