>>1020784
>not even bother connecting tubes, framing, bolts, standoffs, and similar details and just leave them floating on the model
For me it's this. I made pic rel and there are non-connected meshes everywhere (i.e. without merged vertices), I recommend doing things this way because you can simply "glue" pieces onto the chassis of the vehicle (for example, the ladder in the back, the frame of the awning and more) which helps should you wish to make variants: just remove some pieces and swap them out with other new pieces, which would be a problem to do if everything was "fused-in", so to speak.
Vehicles are a great candidate for non-connected meshes, unlike organic characters for example which MUST have continuous topology. Non-organic characters such as robots for instance are another example of good candidates for non-connected meshes

>>1020841
Good effortpost, you learn pretty quickly that not everything has to have connected meshes and that it's more beneficial in this case