I separate the stuff that needs split from the stuff that doesn’t. Big rounds towards the bottom smaller stuff gets thrown on top.
You need some new springs. It ain't safe to ride that low. I picked up a pair of heavy duty springs and love em. Rated for 6k. They carry every bit of that. Sdtrucksprings is where I got mine, no affiliation. They have a huge selection and you can see all the specs.
I try to do the opposite. Smaller stuff down low and bigger up top. Then when I’m splitting, I don’t have to lift the heavies from ground level.
Fortunately, the tw5 has a lift on it for the bigguns! When hand splitting, I just drag the rounds off the top of the pile and use the bigger ones down low to split the smaller ones on.