No, since solder attaches to a larger area and doesn’t ruin the layer structure of the PCB. With spot welds you’re very likely to blast right through the thin copper layer and hit the substrate, thus weakening the surrounding copper adhesion to the substrate. This results in everything starting to peel off easier with external forces, such as vibration. If you solder the copper pads their adhesion to the underlaying layers (substrate) stays optimal.
Also, considering that spot welds(B) are actually tiny, they make a way weaker connection to the copper layer than solder(A) does. And now also consider the fact that you just most likely melted right through the PCB copper layer by spot welding. 
