Simple weldment question?

Hello;

     I usually design product at my company, but was given a test fixture which has to be a simple weldment. My question is if I start with a base plate, & then want to weld a vertical plate to the base plate, should I merge that plate or leave merge unchecked? There will also be a number of gussets supporting the vertical plate & I see that when using the gusset tool, it doesn't seem to merge the gussets. For that reason I'm thinking that I need to keep the plate separate as well. I seemed to have merged the vertical plate but I'm thinking that was a mistake.  Also does it matter when you issue the weldment command in the process.

Thanks in advance for any input

Rob_D SW 2018 sp5.

SolidworksGeneral