I think you are reading way too much into who built it. When the parts are a bolt on, it doesn't take an expert to bolt them on. Not saying someone can't screw it up, but it's not like the '76 Dart Lite they built where it was almost all custom fabrication. The only potential weld on parts are the subframe connectors and even that doesn't warrant the label of "expert built".
I understand that you didn't get the same results with your TB build before swapping to a RMS kit, but it's not because they are experts. It's because you didn't go far enough, (e.g. 383 torsion bars and a 340 Formula S swaybar aren't anywhere near big enough).