There are several body-frame, engine-frame and engine-body ground straps and wires. I left all these intact on my setup, except that I changed the main body-engine strap to a heavier 1/0 cable and that connected that to the same point my other ground cables came up to. Since the starter is the heaviest engine load, the 1/0 cable from the block to ground should handle that. On the way up from the batteries, I reversed the factory wiring a bit, in that I ran the main battery 12V cable to the starter first then up to the engine fuse box. That really seemed to help the starter motor crank over the engine faster. It'll now easily start the truck in 1st gear high range, before only would start it in 1st gear, low range.

Yes, lots of ways to wire batteries up, depends on where they are, how easy it is to get to them and what you want the end system to do.