Yeah, I get what you are saying and have a friend that did exactly what you dream of here. But, the plastic boxes which are easy to steal and break and the low quality rollers where just a waste of time and effort in my opinion.
At the same time I have a friend with a rolling job box and a truck ramp. His box is something like this job box. His box locks securely and he has a bracket that lock the box into the bed of his truck. So he can leave it in the vehicle for long periods with much lower fear of theft.
For me theft is my biggest concern. You can quickly forget how much money you have in your toolbox till you have a box walk away. I use to maintain a job box when I worked with my dad’s company. When I loaned him the box on his trip to India, it got scalped by the local laborers. This was the first time I had to go through my full inventory of tools and replace them. When I did the math, I had lost $4800 in hand tools. Neither my dad or I realized the value until it was gone. We lucked out in the fact that we had fully inventoried the box for customs on the trip. His company understood the issue and funded the replacement of the tools because we had this inventory. The easier you make an item separable and carriable, the easier it is to walk up and steal.
Not saying your want isn’t rational, just saying it is double edged.