> it is good to make sure surfaces join together because joined surfaces makes for shared edges between surfaces, and shared edges between surfaces are necessary to get "watertight" matching meshing for each different surface along that common edge.

Yeah I am used to this concept from learning low-poly modeling during a game prototyping course. We had to keep things "watertight" to avoid getting visible seams during real-time rendering. It has kind of stuck with me and has carried over to MoI, which is why I keep trying to make sure all the surfaces will join together. Thanks for all the tips.