@ Xiarno, zero in functions are unnecessary for static props because they're not moving anywhere. They're just filling up a space and the camera isn't aimed at them 100% of the time...
Zero in, is mainly for cosmetics or items that need to move/animate/interact with a character like clothing/weapons/accessories.

What I did to make the counters and cabinets look seamless was spend an hour experimenting with the scale values and aligning them over and over until they looked picture perfect. It took a few tries for a few pieces because my mouse was not registering my hand movements, or it was registering them too much and pushed the models too far apart when I tried to slide them closer. When they were in the right spots, I copied, pasted, and draged/rotated them to where they needed to go. Nothing special about it. Just a lot of meticulous work.

But isn't their a way (Like with model like cloth) to just lock them & zero them ?

@ Xiarno Oh. You just need to resize them and align them first before you lock them together. I mean, theres no secret to it. Once you line them up lock them together.

Merge / Stick them I don't care whatever works.

Nono, I meant I don't care about the size. I just want to merge them together so they look like one counter like you did.

@ Xiarno: I had to scale the items and lock them in SFM. Even though they're all the correct size and match up perfectly in Blender, in SFM they load them bit off sized.

How do you merge the part so it look like the one in the first picture ?