you could do something similar ish in language to my design
staggered
it’s quite imperative you get that series connection between the “top” and “bottom” levels large enough to spam with spot welds. if you dont have like just oodles of welds that series connection becomes a choke point for current and gets extremely hot,
you can also just fold tge tabs in opposite directions and connect via soldered copper braid/wire
if you spot weld them, make sure you got like some FR4 orrr something similar burn ish resistant tjin and sacrificial. between the tabs and cells to protect them as you spot it up. (no, fishpaper is not a good option, it burns pretty easily)