I'd still probably separate them at the knees just because it can make hip sways easier to animate. You want to keep your cut volumes as simple as you can get away with without points where it caves in a lot, like how the leg does at the knee.
#Cutting layers
ember dew
But I'd also probably do each leg slightly different too. On the character's left, the thigh would be drawn on top of the calf which would be drawn on top of the foot. On the shoed side, since the boot would be over the knee, I'd have the calf drawn above the thigh. The laces make it harder to independently animate the foot so I would see if I could get away with it and the calf being a single piece.
With simplifying layer counts on a full body model, I still wouldn't try to merge the larger, simple volumes of the body together. Like this would be the bare minimum I would try to get away with if I had to and even then I'm not that thrilled about merging the hand with the forearms, but you gotta do what you gotta do.
Otherwise movement will be too stiff and it will be too hard to animate and warp without that separation.
But, again, it depends on the movements you're looking to accomplish. If the hips are going to move, you want that separation between it, the thighs, and the torso. If you don't care about that movement, you can actually probably get away with merging the entire lower half of the body from the hips to the feet and to treat the rig as a half-body model with the lower part mostly being decorative.
What you'll want to prioritize is merging line art, shading, base color, clothing textures, etc of each volume before merging the volumes themselves though.
ember dew
If you have the layer budget, you can actually cut the the straps and glue them to the knee and thigh.
https://www.youtube.com/watch?v=aIOOxhGm8ag
Yeah, you can just take the section that's in blue and have it as a separate layer as it can still be used with the intended effect.
While everything else on the thigh and calf are merged.
And you would just have those two sections of the legs and the leather piece.
Yeah, I probably linked a not great tutorial and that's my bad. I'm not really sure if I know the words right now to find a tutorial. 😂 😩
I've been up all night.
I would just disregard the video for now but since you're still just cutting I would just keep the little strap piece separate from the thigh and calf.
This would be an example.