In the case of the strut brace, or as i've done with the rear turrets in the HPE a tubular piece of tube welded between both turrets. Is purely to strengthen the shell, the same loadings are going to happen to the car, these are now being resisted and being spread across the car at a lower impact than all the load being taken out on one side or at one point, and makes the suspension do its job rather than the body bending and flexing at every opportunity. I know after having all my delta turbo turrets re-welded with thicker metal than standard, I still managed to pull the turrets ever so slightly in with an adjustable strut brace, handles like it's on rails now