Typical switchgear is a bolted frame construction. For the most part, a heaver gauge material will not prevent twisting. Gear must be level and square for drawout breakers to opperate properly.
Proper installation is everything. An option is to order switchgear with a seismic rating. Manufacturers typically add gussets & stiffeners to gear to obtain the seismic rating. This will help to assure that squareness is maintained. In the end though...Good Installation.